Midland Deck Building Requirements. THE CORPORATION OF THE TOWN OF MIDLAND
DECK PERMIT GUIDELINES
BUILDING DEPARTMENT
575 Dominion Avenue
Midland, Ontario L4R 1R2
Tel: 705-526-4275
Fax: 705-526-9971
www.town.midland.on.ca
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TABLE OF CONTENTS
THE DECK PERMIT
Application Process……………………………………………….. 3
Contractor’s Obligation…………………………………………… 3-4
SUBMISSION CHECKLIST FOR DECK PERMIT…………………………………… 5
CONSTRUCTION REQUIREMENTS
Deck Design Statement…………………………………………… 6
Requirements ……………………………………………………… 7
Beam Table ……………………………………………………….. 7
Floor Joist Span Table ……………………………………………. 7
Guards for Housing and Small Buildings
Extracts from the Ontario Building Code…………………………. 8
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THE DECK PERMIT
This booklet provides the homeowner and the contractor with information on obtaining a deck
permit in the Town of Midland. Questions should be referred to the Building Department.
? APPLICATION PROCESS
The first step in the process is to obtain the deck permit guidelines and application form
from the Building Department located at Town Hall, 575 Dominion Avenue. Work
completed prior to an application review may not meet Building Codes and may need to
be redone.
The details of the deck design should be prepared following the guidelines for plan
drawings and structural elements that are provided in this booklet.
Along with the completed application form, the following documentation is required:
• Survey or site plan, drawn to scale, illustrating existing buildings/structures and
the proposed location of the deck.
• Plan Drawings (two sets)
• Completed deck design statement (included with application)
Plans should include:
• Overall deck size
• Beam size and location
• Post size and location
• Floor joist size and spacing, as well as the direction the joists are spanning
• Location and width of stairs (if applicable)
• Height of deck at highest point
• Type of guard (railing) system being used
? CONTRACTOR’S OBLIGATION
Signed Authorization
If a contractor will be building the deck and is applying on behalf of the homeowner, a
signed authorization from the homeowner is required (included with application).
Building Code Identification Number (BCIN)
A Building Code Identification Number, or BCIN, is the unique identifying number
assigned to individuals who file their qualifications with the Ministry of Municipal
Affairs and Housing. As of January 1, 2006, most designers who prepare documents to
be submitted with permit applications, required under the Building Code Act, and who
are not licensed architects must:
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• Be registered with the Ministry of Municipal Affairs and Housing
• Possess provincial qualifications
• Provide information about their qualification and registration on the permit
application form and on all design documents.
Homeowners who are preparing their own drawings for submission and take
responsibility for the design activities of the project are not required to have a BCIN
Number.
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SUBMISSION CHECKLIST FOR DECK PERMIT
The complete application should include the following:
? Completed and signed Building Permit application
? Completed and signed Deck Design Statement
? Survey plan/site plan, drawn to scale illustrating existing buildings/structures and the
proposed location of the deck
? Two sets of plan drawings
? Signed authorization from homeowner (if applicable)
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THE DECK DESIGN STATEMENT
Please ensure that the attached Deck Design Statement is
completed in conjunction with the Building Permit
Application.
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CONSTRUCTION REQUIREMENTS FOR DECKS
• Circular concrete piers to be a minimum of 10 inches in diameter and extend a minimum
of 48 inches below finished grade.
• Piers shall be placed on footing pads or be tapered out at the bottom by 50% to provide
proper bearing and to resist uplift.
• Footings or piers shall bear on undisturbed soil with a minimum bearing capacity of 1500
PSF.
• Size of piers may increase due to soil conditions or spacing.
• Support posts for beams to be a minimum 6 inches x 6 inches for all elevations over 5
feet, 11 inches.
• Anchorage to building with minimum ½ inch diameter bolts spaced not more than 16
inches apart. Deck is not permitted to be supported on brick veneer.
• Beam to post and post to base connections shall be securely fastened to resist uplift and
lateral movement.
• Beam sizes and floor joist sizes to be determined from span tables below. (Note:
minimum permitted joist size is 2 inches x 8 inches.)
• Guard height of 35 inches if top of deck exceeds 24 inches above grade or 42 inches if
top of deck exceeds 5 feet, 11 inches. Guards shall be non-climbable and vertical
balusters shall be spaced no more than 4 inches apart. Provide handrails on stairs if there
are more than 3 risers. Wood guard posts to be a minimum 4 inches x 4 inches (solid).
• Deck blocks can only be used where the deck is not attached to the house, the deck is less
than 55m2 (592 ft2) and the distance from the finished ground to the under side of the
floor joists is not more than 600 mm (23 5/8?).
NOTE: All deck guards shall meet the requirements of the Ontario Building Code SB-7
Supplementary Guidelines or be designed by Part 4 of the Ontario Building Code
(Engineered Drawings).
BEAM TABLE FLOOR JOIST SPAN TABLE
DEPTH OF
LINTELS
MAXIMUM
ALLOWABLE
SPANS
JOIST SIZE
SPACING
SPAN
2 – 2? x 8? 5?- 5? 2? x 8? 12? o/c 11? – 7?
2 – 2? x 10? 6? – 8? 16? o/c 11? – 0?
2 – 2? x 12? 7? – 8? 2? x 10? 12? o/c 13? – 8?
3 – 2? x 8? 7? – 3? 16? o/c 13?- 0?
3 – 2? x 10? 8? 2? x 12? 12? o/c 15? – 7?
3 – 2? x 12? 10? – 3? 16? o/c 14?- 10?
These tables have been provided for your convenience. All plans to be reviewed by the local
Building Department prior to construction.
General Notes:
1. Site plan or survey is required showing all lot lines, dimensions, size and location of all
existing buildings, proposed location and size of deck.
2. All lumber used must be stamped and graded No. 2 or better quality.
3. Maximum cantilever (overhang) for 2? x 8? joists is 16? and for 2?x 10? joists is 24?.
4. 5/4? decking material is only permitted when supported by joists on 16? centers.
***The above information has been compiled from the Ontario Building Code and applicable laws***
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Guards for Housing and Small Buildings
Supplementary Standard SB-7
Extracted from the Ontario Building Code
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CANTILEVERED PICKET GUARDRAIL
4?x 4? support post at Continuous 2?x 6? guard
junction between stair and deck.
Two 3? #7 screws at each picket
4?-0? on centre max.
Handrail construction to match
cantilevered picket rail construction. 4?maximum opening
2 ½”corrosion resistant spiral
nails or screws typical.
3 rows of 3?nails at 12? on
centre.
Dropped framing member into
which each stringer is end nailed
using 3? nails maximum. 2?-11? between stringers.
2 – 3/8? diameter thru bolts with
1 ¼? outside diameter washers.
2? x 4?wood blocking at 4?-0? on centre
minimum between stringers.
Stringers anchored to precast concrete.
Cantilevered Picket Notes:
1. Provide a minimum of 10 pickets beyond the return if end restraint of the guard is provided by this return detail
only. Otherwise, a post is required (see post anchoring above).
2. Pre-drill pilot holes in pickets to avoid splitting.
Typical Stair Construction Notes:
1. Provide a handrail 35? to 38?high on stairs if more than three risers. Provide a guard on both sides of stair where
stair exceeds 6 risers.
2. All steps to be equal rise and run between landings.
Minimum rise = 4 7/8? vertically Maximum rise = 7 7/8? vertically
Minimum tread = 9 ¼” horizontally Maximum tread = 14? horizontally
Asphalt Shingle Burn Out. ACCELERATED ASPHALT SHINGLE “BURN OUT” LEADS TO LEAKAGE ON ROOF RIDGES
Have you ever wondered why hip and ridge asphalt shingles burnout faster along the ridge of the roof than shingles made from the same material on the rest of the roof? The explanation is less obvious than you might think. The asphalt shingles at the roofs’ peak, its ridge line, are being actively destroyed, even during cold winter months, from heat and moisture build-up inside an un-ventilated or poorly vented attic.
As we all know, heat rises. In this case, to the highest point of the attic, right below the ridge line. And it is here that the heat attempts to escape particularly in today’s more tightly constructed homes. The attic in earlier architectural styles was draftier and less energy-efficient than now. Unlike summer’s hot sun, winter provides a different source of destructive heat. Heat from the homes interior rises into the attic, taking with it water vapor, the unnoticeable consequence of such everyday water-related activities as bathing, washing dishes or doing the laundry.
When an inadequately ventilated attic allows this warm, moist air to accumulate, deterioration of asphalt shingles and even of wooden roof structures is the inevitable result. If winters’ less obvious destructive effects are then added to pre-existing burned-out asphalt shingles along the ridge line, your customer can expect either a long, cold winter or higher heating bills than necessary.
Here’s why. After warm, moist air rises into the attic, it cools, releasing its moisture as condensation, which settles into attic insulation. It doesn’t take much moisture to impair the efficiency of attic insulation. In fact, with only a 1% moisture content, insulation loses 36% of its R-value. During winter decreased R-value means increased heat loss from the home. Because the function of attic insulation in winter months is to help keep the homes’ interior warm and comfortable, heat that escapes through insulation is gone forever. Attracted to the cooler roof sheathing and then to the even colder outside air, heat never re-enters the homes’ interior… a chilly prediction for the owners of unventilated or inadequately vented attics.
High heat, whether from outside or inside, will bake the oils right out of petroleum-based asphalt shingles, shortening the warranty period of products intended to last many years longer than they actually do. There’s no way to prevent exposure to the natural forces of sun, wind, rain or snow but you can vastly reduce premature aging of asphalt shingles by providing good attic ventilation on your customers roof, whether new construction or retrofit.
According to university studies, ventilation is most efficient at the ridgeline where heat normally collects. Old-fashioned turbine vents, for instance, are not only less efficient because of where they’re installed but suffer from homeowner dissatisfaction as well. Owners of turbine vented roofs often regard their whirlybirds as necessary evils, but also complain of the noise, leakage and stark unattractiveness associated with using them. Many people, though, including a number of roofing contractors, still don’t realize how much damage attic heat can inflict on an asphalt shingle roof, a fact that has not been lost on regulatory agencies and corporate executives. This is why the Uniform Building Code requires adequate attic ventilation and so do the warranties of every manufacturer of asphalt shingles. In other words, if you install an asphalt shingle roof without the question of attic ventilation being asked or answered you may as well throw out the manufacturer’s warranty along with the shingle wrappers.
In the long run, a cooler, drier attic helps preserve the life of asphalt shingle roofs but what about short term benefits? Of these, the most important is customer comfort. Not only is venting through the ridge the natural way to ventilate the attic, it is also the most cost-effective. Your customer’s home stays warmer during the winter so heaters and furnaces aren’t turned on as soon in the day or left on for as long, resulting in lower utility bills. But what about curb appeal. Sales figures confirm the popularity of texture and dimensionality among homeowners who select designer premium shingle roofs, a feature no less sought-after on the hips and ridges of the roof. But since none of the dimensional hip and ridge shingles also vent the attic space, they’re especially vulnerable to early burnout.
To satisfy the attic ventilation requirements set by the UBC, your customer’s roof should be installed in accordance with a ratio of one foot net free ventilation for every 150 feet of attic space. For example, a single story 2,500 square foot house with 130 feet of ridge would need 16 square feet of net free ventilation… the equivalent of 20 turbine vents or 128 feet of through-the-ridge venting.
Polyurethane Foams for Low Pressure Injection Crack Repair
Concrete Crack Repair for Foundations. What is the better choice: polyurethane or epoxy? Epoxy is the better choice if structural strength is required to be maintained. If the crack is only repaired to prevent water leakage then either product can accomplish this task.
Cause of Cracks
Lack of joints, to accommodate drying shrinkage and thermal movement during the construction phase is one of the major causes of concrete cracks. Settlement and overloading are also common causes of cracking. Cracks usually appear within the first month after construction. These cracks can leak as soon as they are formed or might expand and leak later. Crack can grow and cause problems as they expand.
How Cracks Grow
Moisture, which is the worst enemy of homes, enters the tiny cracks in the concrete and in colder weather, freezes, enlarging the crack. Also, movement of soils surrounding your home, through settling, can also cause expansion of your cracks. In extreme cases, soils that are unstable can overcome the inherent strength of concrete causing crack and expansion.
Cracks caused by construction, heat, freezing and settlement can be corrected by injection. Cracks caused by unstable soils must have soil problem stabilized prior to attempting injection corrective methods.
Low Pressure Injection
This method of injecting polymers into the concrete is adequate for repairs of cracks not involving high volumes of water. High-pressure injection is better suited for this type of application. Low pressure is defined as injection pressures between 20 to 40 psi and can be used with either ports or surface injection. Pressures as high as 250 psi may be used.
High Pressure Injection
1,000 to 10,000 psi utilizing injection packers usually placed in holes drilled at 45 degrees to intersect the interior of the crack. This is common method of repair using polyurethane foam. High cost of packers, clean up of excess, potential stress damage and dangers of using high pressure are overcome by using low-pressure injection methods.
The use of surface ports (with one-way check valves) together with low-pressure injection of a sealed crack eliminates these problems in most situations. The injection of high-density foam is an effective water proofing method.
The best method for low-pressure crack repair is to slowly inject liquid polymer into crack until crack is completely filled, filling of adjacent surface port is visual confirmation. Using pressures above the 40-psi will allow polymer to rise and may indicate a false presence of the polymer filling voids.
Methods of Surface Sealing and Placing of Surface Ports
Surfaces are first cleaned with wire brush, and then surface ports are placed along crack at intervals equal to the thickness of the wall. The surface crack is then filled with epoxy paste which when sufficiently hardened allows filling of surface ports to begin. Hydraulic cement is used when cracks are actively “wet”. The ports must then be anchored to prevent blowing off during injection.
Brought to you by the Alliston Home Inspector
New Home / Pre-Delivery Inspections in Barrie – Many new home buyers will see their new home for the first time during their PDI inspection. Most builders do not encourage buyer to visit the new home site during construction, siting insurance concerns, but other builders welcome purchasers and allow them access to their home during construction.
Your Pre Delivery Inspection is a mandatory inspection required by Tarion and is conducted using Tarion’s checklist or a similar list supplied by your builder.
Many home owners are over whelmed by the prospect of inspecting their new home and often hire a professional home inspector to accompany them during the PDI inspection. I personally always recommend that the home owner notify the builder in writing that they will be bringing a home inspector as some builders are very resistant to having a professional inspect your home.
I recommend that the home owner bring a copy of the Tarion check list that is available on their web site and keep track of all items that they have looked at and any deficiencies that require the builders attention. As a professional home inspector I use a more in depth check list which covers basically but not limited to the following:
- structural components including foundation and framing, including probing a representative number of structural components where deterioration is suspected or where clear indications of possible deterioration exist.
- exterior wall covering, flashing and trim.
- exterior doors.
- attached decks, balconies, stoops, steps, porches, and their associated railings.
- eaves, soffits, and fascias where accessible from the ground level.
- vegetation, grading, surface drainage, and retaining walls on the property when any of these are likely to adversely affect the building.
- walkways, patios, and driveways leading to dwelling entrances.
- roof covering.
- roof drainage systems.
- roof flashings.
- skylights, chimneys, and roof penetrations
- interior water supply and distribution systems including all fixtures and faucets.
- drain, waste and vent systems including all fixtures.
- water heating equipment.
- vent systems, flues, and chimneys.
- fuel storage and fuel distribution systems.
- drainage sumps, sump pumps, and related piping.
- electrical service drop.
- electrical service entrance conductors, cables, and raceways.
- electrical service equipment and main disconnects.
- electrical service grounding.
- interior components of electrical service panels and sub panels.
- electrical conductors.
- electrical over current protection devices.
- a representative number of installed lighting fixtures, switches, and receptacles.
- ground fault circuit interrupters.
- installed heating equipment.
- heating vent systems, flues, and chimneys
- installed central and through-wall cooling equipment.
- interior walls, ceilings, and floors.
- steps, stairways, and railings.
- countertops and a representative number of installed cabinets.
- a representative number of doors and windows.
- garage doors and garage door operators.
- insulation and vapour retarders in unfinished spaces.
- ventilation of attics and foundation areas.
- mechanical ventilation systems.
- fireplace system components.
- fireplace vent systems, flues, and chimneys.
Every house is different and each inspection will identify items that are unique to that particular home. There are many similarities to deficiencies found while inspecting homes but as homes are built by humans there is the possibility for almost any conceivable mistake possible to be present.
New home warranty (Tarion) inspections are performed just before the one or two year builders warranty is about to expire. This type of inspection is similar to our other services, however emphasis is placed on construction issues that may have arisen during the first year or two of ownership.
Some home inspectors argue that cosmetic damage is not within the scope of the Tarion PDI inspection. I differ on this completely. It has been my experience that home owners that do not make a note of minor dents, scratches on floors or cupboards etc on their PDI, find that when they identify them on their 30 day list the builder has disputed the fact because they were not included on the initial PDI checklist. Not all builders are cut from the same cloth but I have encounter circumstances where the client had to chase after the builder who had got them to sign off on the PDI before completing inspection. He had told them that it was not a “big deal” and just to list everything on the 30 day inspection report.
Floor Drains and Primer Lines – What is this??
Have you ever just been casually looking around in your basement, typically around your furnace area, and thought: what is this?
Well the “what is this?” is infact a priming line for your floor drain.
Let’s start at the beginning here.According to the Ontario Building Code and the National Plumbing Code, a floor drain must have something called a trap seal, what this means is that there must be water in the trap to prevent sewer gas from coming into the house.
What is a trap? It is a pipe that is either formed or pieced together to form the letter P (this is one of the common traps that we’ll discuss) .They are found in such places like under sinks, under showers, and of course they make up part of the floor drain.But because the traps in the floor drains do not get used as much as traps elsewhere in the house, the trap seal dries up and allows sewer gas and other smells into the house.This is the importance of a priming line.
So what’s a priming line?A priming line is a plastic or metal water line that is attached at one end to something that when in use, supplies water to another location.In most cases the priming lines are connected to the taps on your laundry tub, the taps in the kitchen (under the counter) and attached to the toilet tank (running up the back side of the tank).From their connection point they run through another pipe and eventually end up connected to the floor drain to maintain the trap seal – stops in the intrusion of sewer gas.
What if you don’t have a primer line – what do you do?You can make sure that all traps have water in them simply by running the taps for a few moments.Take a container, pour it down the floor drain, if you have a bathroom in the basement that you hardly use, run the taps in the sink and tub/shower.If there is a laundry tub that is not used to often…again, run the taps, get that trap seal working again.
By doing all of the above, you will maintain the trap seal, you should be minimizing the chances of sewer gas into the house and eliminating any unpleasant odours that make occur.
Brought to you by: The Alliston Home Inspector
Midland Cottage and Home Inspections. The very first thing a person needs to know is what qualifications his inspector has? The Midland Home and Cottage inspector is a Certified Building Code Official by the Ontario Building Officials Association, The only home inspector to have this designation North of Toronto. Basically, this just means that, rather than the two basic courses that most “home inspectors” have, the Midland Cottage and Home inspector has over 13 recognised Ontairo Building Code courses. These courses are all over 1 week in duration and the applicant must obtain over 70% pass mark for each qualification. For a complete list of training and courses that the Midland Home and Cottage Inspector has obtained, please visit Qualifications
With over 3,000 paid home and WETT inspections our expertise is available to assure you peace of mind when purchasing a property. Every summer we inspect cottages from Rama to Tiny Beaches, Innisfil up to Midland and Penetang. Severn River, Kahshe Lake, Sparrow Lake, Georgian Bay and Lake Simcoe are just a few of our common inspection areas. Our experience ranges from the $400,000 entry level cottage to the $2,000,000 dollar dream home.
Inspecting mulit-million dollar properties is not un-usual for us as we have inspected commercial properties for our corporate clients that vary from 1.5 million to 10 million dollars. These commercial properties are not an every day occurance but just to give you an idea of our experience and training, which you get the full benefit of when using our services.
We were the first company to bring Thermal Imaging to Simcoe County and we bring a fully equiped truck to all our inspections. We take our inspections seriously and would never think of showing up in a car with a fold up ladder. We bring 3 ladders to all our inspections, 30 ft, 24 ft and 12.5 ft, if you want a professional job then you must hire a professional.
Our cottage inspections start at $399.00 in the local area, prices may vary according to distance required to travel. Our home inspections start at $399.00 for a single residential home
If you require a WETT inspection we are happy to provide that service for you. Our fee for a WETT inspection during the Home or Cottage Inspection is $50.00 per unit.
Want some important information on inspections and maintenance of your home then do a search on our Tips Web Site, where you will find lots of money saving advice for home and cottage owners.
For the most qualified inspection and for free information and advice please feel free to call me at 705-795-8255 or Toll Free at 888-818-8608
All inspection services come with an un-conditional Money-Back Guarantee.
Carbon Monoxide Detectors Ontario and Barrie Regulations
Location
As per section 9.33.4.2 of the Ontario building code, where a fuel-burning appliance is installed in an occupied residence, a carbon monoxide detector must be installed adjacent to each bedroom in the house. If you have a fuel-burning appliance installed in a service room that is not a bedroom, a detector must also be installed. The city of Mississauga’s by-law defines a service room as any room located in a multiunit residential structure, which is not a dwelling unit or within a dwelling unit.
Installation
Section 9.33.4.3. requires that a carbon monoxide detector be permanently connected to an electrical circuit and it should not be disconnected; all detectors should be activated within your residency suite, and it must be equipped with an alarm that will be heard within the bedrooms when the doors are closed. It is your responsibility to ensure that a detector is in proper working order.
With the increased winter chill comes a rise in the danger from deadly carbon monoxide gas – “CO”. The odourless colourless tasteless
two molecule Carbon Monoxide gas is a by-product of incomplete combustion and combustion without proper ventilation. It accounts for
greater mortality and morbidity than all other poisonings combined. It is a sly and silent killer. Carbon Monoxide gas can quickly build up
to dangerous levels and knock you out before you realize what is happening.
Carbon Monoxide enters blood system through lungs and displaces oxygen. Carbon Monoxide quickly binds with hemoglobin with an
affinity 200 ~250 times greater than that of Oxygen to form Carboxyhemoglobin resulting decrease in arterial oxygen content. Fetal
hemoglobin has much higher affinity for Carbon Monoxide than adult hemoglobin; thus a fetus may be more susceptible to toxic effects
than mother. Pregnant women with only moderate Carbon Monoxide poisoning have had devastating fetal outcomes. Carbon Monoxide
is also an abortifacient and a teratogen, resulting in physical deformities and psychomotor disabilities. Intracellular uptake of Carbon
Monoxide is a mechanism for neurologic damage and cognitive defects, particularly in memory and learning, and movement disorders
that may not appear for days following the initial poisoning. The brain and heart are very sensitive to Carbon Monoxide poisoning; other
organs are also affected.
Awareness of the symptoms of Carbon Monoxide can lead to early intervention and prevent needless deaths. The symptoms of Carbon
Monoxide poisoning are headache, dizziness and nausea.
In 2003 in Ontario, 9 people were seriously injured and 4 died from Carbon Monoxide poisoning. From 1999 to 2003, at least 17 people
have died from Carbon Monoxide poisoning in Ontario. From 1998 to 2001, The Ontario Fire Marshall investigated 47,278 Carbon
Monoxide incidence, though the vast majority were not serious cases.
Incomplete fuel combustion and a vent system that does not adequately remove the exhaust are the two basic failures to all combustion
appliance Carbon Monoxide problems and very often these two failures are interrelated. For example, during backdrafting all the
products of combustion spill into the room housing the appliance leads to the appliance to breathes its own fumes, which causes
incomplete combustion and Carbon Monoxide is produced.
Faulty Home heating systems, propane, kerosene or gas heaters, car exhaust including plugged tail pipes, barbecues and blocked
chimneys can cause a build up of Carbon Monoxide.
Preventing indoor Carbon Monoxide problems is not impossible. Proper installation and regular maintenance of combustion appliances
by trained and qualified heating contractors reduces the possibility of Carbon Monoxide emissions and venting failures. Installing reliable
Carbon Monoxide detectors is the simplest way to detect the presence of Carbon Monoxide. But only 40% of homes have Carbon
Monoxide detectors. And of the homes that have the detectors, only about 25% check their batteries regularly. Carbon Monoxide
detectors should be installed near heating system and in sleeping areas. Properly installed detectors monitor Carbon Monoxide levels
over time and are designed to sound an alarm before an average, healthy adult would experience symptoms of poisoning.
Carbon Monoxide detectors do have limitations. Some may not provide adequate warning if Carbon Monoxide increases to very high
levels. Infants, the elderly,and people with heart or breathing problems are at increased risk for low level poisoning and may experience
symptoms before an alarm sounds. Thus, a Carbon Monoxide detector is not a substitute for proper use and regular maintenance and
inspection of all potential sources of Carbon Monoxide.
Many Home owners report Carbon Monoxide detector going off, but find their contractor unable to diagnose the cause since Carbon
Monoxide sources elude the contractors. Identifying the source of Carbon Monoxide is not simple. Many contractors misdiagnose the
problems. For example they may claim the problem was Carbon Monoxide detector though Carbon Monoxide problem was evident or
say the problem was caused by freak occurrence in the weather and would not happen again.
The causes of Carbon Monoxide are varied as unvented appliances, use of gas cookers for heating, portable space heaters, hibachi and
charcoal cookers, heat exchanger failures, lack of combustion air, overfiring, depressurization of the combustion appliance zone causing
back drafting, vent failures or vehicle running in the attached garage. Any of these might set off a Carbon Monoxide detector, but
conditions may have changed by the time the contractor arrives at the house to identify the source. For example, back drafting of furnace
might set off a Carbon Monoxide alarm but if a window is opened, the pressure in the combustion zone will change. This could reverse
the backdrafting and change the reading on the Carbon Monoxide detectors. Down drafting of combustion appliances, running vehicles
in the garage, depressurization from kitchen fans, bathroom fans, dryer, central vacuum & attic vent fans, wind and charcoal grills are
usually intermittent problems and easy to overlook during investigation.
Combustion products usually go up the vent, but certain conditions may cause them to spill at the draft diverter or out the burner ports.
Buoyant (lifting)forces that cause combustion products to vent result from temperature differences. The buoyant forces are small and
easily over powered by other, more powerful forces. The buoyant force is usually around 5Pa, is only 1/6 oz in a 4in diameter round vent
pipe. Wind forces, exhaust fans and the furnace blower are all more powerful and can reverse the flow in the vents. Combustion
appliances also compete for air. For example, when a fireplace and furnace are both operating they both need combustion air. If the
house is tight, they will compete with each other for combustion air they need.
Technicians often hold a match near the draft hood to check for proper draft, and this method is suggested by some manufacturers.
However holding a match is not good way to check, because the match is a hot source, and the smoke will tend to rise even if it is not
being pulled up into the draft hood. Instead, technicians should use a smoke stick of neutral density, such as those used to check for
infiltration during house leakage tests.
Vent failures are often sporadic, intermittent and difficult to reproduce. Because pressure differences are small, it takes only a small
change to cause warm gases to vent incorrectly. Often a down draft will occur when house is closed. Simply opening the front door once
can change the pressures, allowing warm air to go up the vent again.
A properly adjusted gas furnace or water heater produces hardly any Carbon Monoxide. When too much gas is supplied to the burner,
sufficient oxygen does not flow to the burner and Carbon Monoxide is produced. I find overfiring to be the more common cause of
Carbon Monoxide problems in a Home than heat exchanger failure. Overfiring often occurs in conjunction with intermittent vent failure and
is therefore difficult to diagnose unless proper procedures and equipment are used. Overfired units typically still burn with a blue flame.
Too often, without proper test instruments, the heating contractor will assume that the unit is burning clean.
The difference between a properly adjusted furnace and a overfired furnace are extreme. An overfired furnace can produce more than
4500ppm Carbon Monoxide in the vent. A simple reduction in gas pressure, which takes two minutes to perform, can bring Carbon
Monoxide levels back to below 20ppm.
How do excess gas pressures occur? Sometimes, the gas regulator can fail, or in some cases the installing contractor does not perform
the initial gas pressure adjustment. In yet other cases, the heating contractor or homeowner, desiring more heat, may increase the gas
flow by changing the gas pressure adjustment. Overfiring may also caused by improper orifices, which can result when units are changed
from propane to natural gas or from natural gas to propane. Manufacturers typically desire no overfiring beyond a tolerance of +2%. Yet I
find units 25% overfired. Because overfiring can not be diagnosed by flame colour, it is vital that all heating contractors perform the
following steps:
1/ Check the rate of gas flow to the burner, and check for overfiring by clocking the meter(In other words using the test dial on the gas
meter to verify that the appliance is using the proper amount of gas)
2/ Check manifold gas pressure using an accurate manometer.
3/ Ensure gas orifices are correct
4/ Measure Carbon Monoxide concentrations in the combustion products.
Holes or cracks in the heat exchanger which keeps the furnace exhaust from mixing with house air, can cause Carbon Monoxide
problems. Holes and cracks can allow exhaust to enter the duct system and be distributed throughout the house and also allow air from
the blower to enter the burner chamber and disrupt burner operation, increasing the amount of Carbon Monoxide produced. Airflow
through large holes or cracks can cause combustion products spillage at burner ports – a very dangerous situation. High efficiency
furnaces also have a secondary heat exchanger, which removes heat from exhaust gases causing them to condensate.
Some of the causes of premature heat exchanger failure are:
1/ Incorrect temperature rise – The temperature can be either too high or too low caused by incorrect blower speed selection,
restricted or insufficient duct work, dirty filters or missing filters. The correct range for temperature rise is on the information plate of each
furnace.
2/ Contaminated indoor air – Contaminants like chlorine fumes from the nearby laundry machines, paint thinners and aerosol sprays
are hard on high efficiency furnaces as they create acids in condensation, which attributes to corrosion. Use sealed combustion to
prevent corrosion from contaminants.
3/ Incorrect gas flow rate – Many units are overfired, running rich and hot. Overfired units do not have sufficient air for complete
combustion. Cracking of heat exchanger, sooting and Carbon Monoxide can result from overfiring.
4/ Oversizing – This causes rapid on / off cycling without sufficient time to heat the furnace exchanger or vent. Condensation forms
and does not get evaporated out. The “wet time” is excessive.
Carbon Monoxide poisoning is the leading cause of poisoning deaths in North America. To often people think that CO poisoning can not
happen to them, since they live in a drafty older house or have a new furnace. This is not true as Carbon Monoxide poisoning can occur
in older loose houses or newer tight houses and can be caused by new furnaces as well as old ones.
Thermal Imaging and Home Inspections. Thermal Imaging has made a significant impact on the Home Inspection industry with the reduction in costs associated with owning a Thermal Imaging Camera. Investing in new technology has always been a priority with my company and we were the first Home Inspection company in Simcoe County to offer this Free service with our home inspections. Even Mike Holmes has been a vocal advocate of Thermal Imaging Cameras and I believe all his “home inspectors” now offer this service as part of the Mike Holmes package.
Thermal imaging is not magic, some people will try and convince you that it is, but simply a device that measures light that the human eye cannot see. You can buy Infrared film for you older style film cameras and take your own Thermal Imaging pictures. There are even animals who naturally have the ability to see images in the infrared spectrum. Thermal Imaging is a tool that can aid in finding missing insulation, electrical hot spots, moisture problems, water leaks, in-floor heating problems, flat roof problems and finding where plumbing or electrical cables are located prior to renovating. This is not magic, no more than using moisture meter or video camera snake for inspections.
Lack of or missing insulation can be detected with the proper use of thermal imaging cameras except that unless there is a temperature difference of over 10 degrees the information is basically useless. Thermal imaging will only measure differences in temperature and is unable to measure the thickness of your insulation. If the temperature difference is not extreme then the insulation will perform its job even if not installed to required R value. So as you can see Thermal Imaging does have its limitations.
Moisture can also be detected by use of Thermal Imaging camera, but once again only by detecting the visible change in temperature in the infrared spectrum. So while the moisture may be behind a wall it will affect the temperature on the surface which is what the Thermal Imaging displays.
Thermal imaging can be deceptive to the in-experienced user. I have personally come across situations where electrical cables have been identified as foundation cracks and drywall corner beads have been determined to be water leaks. Imagine the shock to that home owner, especially when in-accurate information was provided.
Beware of individuals promoting Thermal Imaging as a “magical” see through your wall technology. Infrared cameras are just another tool, which when used with experience and knowledge, become part of a professional home inspectors array of tools to bring you the best possible home inspection. If your home inspector is misleading you about what Thermal Imaging is what else are they misrepresenting?
Caveat Emptor = Buyer Beware
An educated consumer is a smart consumer. Always ask questions and check with two or three professionals before making a commitment.
Arc Fault Electrical Basics. Although new to the NEC, AFCIs are important for protecting against arc faults.
Unsafe arc faults can occur as series or parallel arcs. A series arc can occur when the conductor in series with the load breaks. The series configuration means the arc current cannot be greater than the load current the conductor serves. Typically, series arcs don’t develop sufficient thermal energy to create a fire.
More dangerous is the parallel arc fault, which can occur as a short circuit or a ground fault. A short circuit arc decreases the dielectric strength of insulation separating the conductors, allowing a high-impedance, low-current arc fault to develop that carbonizes the conductor’s insulation, further decreasing the dielectric of the insulation separating the conductors. The result is increased current, exponentially increased thermal energy, and the likelihood of a fire. The current flow in a short circuit, parallel arc fault is limited by the system impedance and the impedance of the arc fault itself.
A ground fault parallel arc fault can occur only when a ground path is present. This type of arc fault can be cleared by a GFCI or an AFCI. The RMS current value for parallel arc faults will be considerably less than that of a solid, bolted-type fault. Therefore, a typical 15A breaker might not clear this fault before a fire ignites.
UL 1699 contains the requirements for listing AFCI devices. Each type of AFCI protects different aspects of the branch circuit and extension wiring. However, only the branch/feeder AFCI meets NEC requirements. AFCIs are not designed to prevent fires caused by series arcing at loose connections. Let’s look at examples of AFCIs.
Branch/feeder AFCI.
This device is installed at the origin of a branch circuit or feeder like a panelboard. It provides parallel arc-fault protection for branch circuit wiring, cord sets, and power supply cords. It’s not UL-Listed to provide series-type arc-fault protection.
Combination AFCI.
This device, which is typically a receptacle, provides parallel and series arc-fault protection for branch circuit wiring, cord sets and power supply cords downstream from the device. It doesn’t, however, provide parallel arc-fault protection upstream.
Outlet circuit AFCI
This device is installed at a branch circuit outlet. It provides parallel and series arc-fault protection for the cord sets and power-supply cords plugged into the outlet. However, it doesn’t provide arc-fault protection on feed-through branch circuit conductors, nor does it provide parallel arc-fault protection upstream from the device.
Although AFCIs have their uses, it’s important to note that these protection devices are not designed to prevent fires caused by series arcing at loose connections in devices like switches or receptacles.
Article by Mike Holt
Barrie Real Estate Agents
Greenfield DND IRP Information
Ontario Building Code and Large Buildings
Most home inspectors take a couple of basic Part 9 Ontario Building Code courses as part of their education. The two courses taught by Georgian College as part of their evening home inspection course covers the basics of the building envelope and structural requirements of buildings under 600 m2, of residential or mercantile occupancies or being three stories or less in building height. Part 3 building inspections require a whole new skill set and qualifications beyond the scope of these part-time evening courses. These courses are typically only available in larger centers such as OBOA teaching facility in Toronto.
The Construction Type of buildings is very important when inspecting large buildings. There are two principle types of construction, combustible and non-combustible. Non-combustible construction must meet the criteria set forth in CAN4-S114 “Standard Method of test for Determination of Noncombustibility in Building materials.
Combustible construction has a higher flame spread rating and is usually limited to smaller buildings where fires can be more easily controlled by firefighters.
There are combustibles that are permitted in combustible construction and they are items like paper covering on gypsum, caulking, window sashes, wood trim and some fixtures.
Insulation is an example of a combustible product that must have a thermal barrier installed in order to be used in a building of non-combustible construction. The type of insulation thermal barrier is based on many items such as height of building, sprinklered, location (interior or exterior) and occupancy classification.
Fire separations refer to an assembly that acts as a barrier against the spread of fire or smoke and fire resistance rating refers to the amount of time it withstand before failing. Know what they are and being able to determine the FRR that is required is a very important part of inspecting commercial buildings. Any penetration of a required fire separation must be fire stopped or protected by a rated closure. Every occupancy has different requirements and may or may not require a fire résistance rating. Some fire separations require no FRR and are designed to hold back smoke.
Many vertical fire separations are penetrated by horizontal services such as plumbing, heating and electrical. This services must be constructed of approved material, fire stopped, enclosed in FRR shafts, protected by closures or fire stopped if constructed of an approved material.
Closures include doors, windows and fire dampers which all must have a FRR required by Ontario Building Code requirements. All hardware installed on closures in fire separations must be approved for use and be listed by recognized agency such as ULC.
This is the first in a series of articles being written on Large Buildings as defined by Ministry of Municipal Affairs and Housing and Ontario Building Officials Association. Visit for more information
