Articles by Keith Tripp

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Sump Systems and perforated basins.

perforatedPerforated sump basins used for a standard foundation drainage system are the wrong tool for the job, yet are common in new construction in the Toronto, Ontario, Canada area. They are full of holes (no surprise!) so water entering the basin will escape to surrounding soil under the slab, until it is fully saturated. When I test these basins by pouring water in, it will often escape and not activate the pump. The pump will only activate if the surrounding soil or other materials acts as a well and allow the water to rise.

The codes (OBC) and common sense say that storm water may discharge to a sump or drywell or to “daylight” ( outside to a drainage ditch) but NOT to the underside of the slab.  The codes do not specify what type of basin is to be used, and unfortunately City building officials accept the perforated basins.  This doesn’t make it right. Rather it shows weakness in their understanding of the requirement and interpretation of the code.

Ontario Building Code 9.14.5.  Drainage Disposal: 9.14.5.1.  Drainage Disposal (1)  Foundation drains shall drain to a sewer, drainage ditch or dry well.

9.14.5.2.  Sump Pits (1)  Where gravity drainage is not practical, a covered sump with an automatic pump shall be installed to discharge the water into a sewer, drainage ditch or dry well. NOT UNDER THE SLAB

Collecting all the water from the perimeter of the foundation drainage, and discharging it all under the basement slab close to the footings just is not a good idea. There is a code statement that could apply to this:

Ontario Building Code Section 9.16.  Floors-on-Ground: 9.16.3.  Drainage: 9.16.3.1.  Control of Water Ingress (1)  Except as provided in Article 9.16.3.2. or where it can be shown to be unnecessary, ingress of water underneath a floor-on-ground shall be prevented by grading or drainage.

A solid basin is the right tool for standard foundation drainage systems. The perforated basins are intended for collection from problem soil areas, and would typically be installed in a central location, surrounded by granular fill that facilitates water flow towards the basin.  The perforated basin may also act as a well and collect water from deeper than necessary. Most basins are about 24 inches deep. Digging a 24 inch hole under the house is likely to attract water from the surrounding soil, and this can result in significant and unwarranted water collection.

To collect or convey? Poking holes in the use of Perforated Pipe

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A perforated, corrugated drain pipe.

by Keith Tripp, 2020

Sump systems used to be associated with rural properties or older house. Sumps are now, for about the last 15 years or so, making a comeback in new construction. They are installed in new subdivisions where the City does not want to assume the risk of damage to houses caused by storm system backups, and on new construction in areas with older infrastructure, where the height of the house foundation drainage system may not match the existing City storm water system.

Staring down the barrel of this sump infeed pipe, a few things become evident:
a) this is a perforated pipe with slots cut around the circumference.
b) there is no top or bottom to the pipe, it is installed with random orientation
c) the pipe looks quite clean, there has not been much water flow through the pipe

Add in a dash of common sense: a pipe full of holes will lose water unless it is submerged in water.
Conclusion: this is the wrong pipe to use as a sump infeed.

This pipe is deigned to collect water from the surface of saturated and compressed soil . This is the type of pipe commonly used here in the Toronto, Ontario, Canada region for foundation drainage around the perimeter of the footings. As per OBC (Ontario Building Code) they are OK as COLLECTION pipes to be installed alongside the footings, with the top of the pipe being below the level of the underside of the basement floor slab, and must be installed on undisturbed or compressed soil (not on gravel) and installed level, not sloped. In this application, the pipe will collect water that rises above the level of the saturated soil. Rising water will enter the pipe through the slots, then seek the path of least resistance, which will cause it to flow through the pipe until an escape route is reached. That escape route may be out through the slots in areas where the soil is not saturated or where there is no water above the soil surface, or it may be the ends of the pipe where it terminates at the sump basin, or flows in to a City storm system, or to “daylight” if the house is built on a hillside. So in theory, ( the theory being the assumption that the pipes are installed level and on compressed soil), the pipe is moving water from wet areas to dry areas, until all areas are wet and then flow out of the pipe will occur. This may explain why some some sump basins are always dry, the pipe may just be moving water from the wet side of the house, to the dry side of the house where it dissipates in the soil.

If the pipe is installed on gravel. It will only collect water that rises above the gravel, and it will quickly lose water back on to the gravel. Pipes installed on gravel or  are basically useless.

To pass from the exterior to the interior where the sump basin is installed,  pipes will pass through a sleeve in the footing.  Water will be lost at this sleeve if a perforated pipe is used. At the areas around the sump basin, there is often gravel, and the soil has been disturbed by the digging and installation of the basin. A perforated pipe will lose water as it approaches the basin. This can be a considerable volume of water, as it has been collected from the full perimeter of the house. This water may cause erosion damage, or weaken soil by ongoing cycles of saturation and drying.  Sump basins are typically installed just inside the basement wall, where they are close to the structural footings. Long term soil weakening around or under the footings is undesirable, and may result in movement of the structure.

The pipes passing through or under the footing and under the basement slab to the sump basin should be solid pipes (not perforated) that CONVEY water without losing it along the way.  These are the pipes that connect the foundation drainage pipe (a.k.a. weeping ) tile, to the sump basin which acts as a collector. From the sump basin, the water will be pumped to the exterior.

Cold Room Conversions

cold roomby Keith Tripp, 2020

 

A client recently asked about converting their cold room space to use as conditioned storage space or a wine cellar. Cold rooms are typically located underneath the front entrance porch and stairs. The walking porch surface is the concrete ceiling of the cold room. The sides of the cold room are poured concrete , similar to the main foundation walls. Brick is sometimes installed on the sides of the cold room walls above ground, but this is installed as decoration and is not required to be a draining veneer wall.

 

 

Here are some of the some considerations for converting a cold room here in the Greater Toronto Area, Ontario, Canada.

  • Cold rooms were not built as living space, and are often subject to water leakage especially under entrance stairways where there will be melting snow in the winter
  • Cold rooms are uninsulated, so require the addition of insulation and vapour barrier and possibly an air barrier if being used as heated space or even a cool space.
  • Cold rooms are not built to meet an air barrier standard. To the contrary, they are vented to the exterior. Even though concrete makes a good air barrier, an air barrier may be required to compensate for openings at joints.
  • The walls and ceiling of cold rooms are solid concrete, without a vented cladding wall. They are likely to be subject to inward solar driven vapour diffusion. This means vapour barrier selection is important. This would be a good application for a “smart” vapour barrier.
  • Cold rooms are vented to the exterior, so if being converted to heated space they require air flow to be connected (so installation of ductwork) and blockage of the venting to the exterior.
  • Proper wine storage requires temperature control and usually the installation of a refrigeration unit

 

Reduce rip-off risk: Do a really good home inspection on your existing home.

Home inspections are not just for buyers or sellers. Having a professional inspection of your existing home can reap benefits for years to come.

I recently did an inspection where the sellers were providing an inspection report from 4 years ago. This report was one of those useless checklist types in a small binder. It contained many pictures of theoretical conditions that did not apply to the house in question. I flipped through it, and struggled to find any issues identified with the house. I thought that type of report had disappeared long ago, but I guess they are still out there. This is the type of inspection and report that has given the industry a bad reputation over the years, and contributed to the call for licensing of the profession. It was a reminder that the report I have developed over the last 13 years is probably one of the best available in the home inspection market. As an aside, if you are a home buyer, keep in mind a 4 year-old home inspection is too old to be relied upon. A lot can happen in 4 years. At this house, a foundation crack had opened up considerably since a parging coat had been applied. That parging was fresh when the last inspection was done, and the foundation cracks would have been concealed.

The ProVantage report is written in an Issue-Action-Risk format. What I saw- the recommendations-risks of inaction. It is written in full sentences that make sense, not cryptic jargon. Each issue (defect) is assigned a priority of 1,2 or 3, with 1 being the highest. The report comes in two parts. Firstly, the full electronic report with defect photos, issues and description of the house. Secondly a word document list of issues in table format. The table can be sorted or cut and pasted as required. This table becomes the to-do list.

Consider a home inspection on the home you already own, for the following benefits:

1)     Separate the important issues: Often homeowners are stressed about issues that may not be that important

2)     Reduce risk of contractor rip-off. Knowing priorities and risks means you can make smarter purchasing decisions.

3)     Develop a to-do list and rough budget for the upcoming years.

House Shopping 101: “Don’t worry, the City inspected it!” #7: HRV intake terminal incorrect

This is the seventh in a series on construction defects found in the Greater Toronto Area, Ontario, Canada. The header photo shows an HRV. This HRV is red and flashy and has a continuously variable transmission all wheel drive. I don’t know how Honda picked the HRV name, but HRV in the residential building world stands for heat recovery ventilator. The HRVs I want to talk about are quite boring and are tucked away in the basement where most homeowners can ignore them.

 

hrv2An HRV is a system that ventilates the house with fresh air and recovers heat from outgoing air. There is also a similar system called an ERV (Energy Recovery Ventilator) that recovers heat from the air and heat from moisture in the air.  Photo at left shows a typical HRV installation. In this photo the front cover of the box is open. Note the two insulated hoses at the left. Those are the two hoses that connect to the exterior.

Most new high-rise condominium units are now equipped with ERVS, often integrated with the bathroom exhaust system. Some houses built in the 90s and 2000s may have an HRV installed, but until now, HRVs were not that common. Many houses built since 2012 have HRVs installed as part of the builder’s energy compliance package options.

HRVs (and ERVs) have two connections to outside air. One is an intake and one is an exhaust. The exterior terminals are easy to find because they are quite large and close to the ground. The exception is on townhouse units where the terminals may be higher up and may be in the form of a single concentric combination intake/exhaust terminal.

A common defect I find related to HRVs is installation of the incorrect type of intake terminal at the exterior. The intake must be an “always open” type terminal with fixed louvers and a screen.

hrv3This photo shows an HRV intake terminal that is correct. It is an “always open” terminal with a screen. The paper is being drawn in against the terminal when the HRV is in operation.

 

 

 

 

hrv4This photo shows an HRV intake equipped with the incorrect terminal. The terminal is designed as an exhaust terminal. It has louvers that will open when air is blowing outwards. When this type of exhaust terminal is installed as an intake terminal for an HRV, it slams shut and no air can flow inwards. It’s never a good idea to violate the code of common sense. Unfortunately, there is no indication to the homeowner that the HRV intake is blocked. The HRV will continue to run without any sort of warning. I have found the incorrect terminal installed on a 10 year- old house. For 10 years the HRV intake had been “dead heading” and not bringing in any outside air.

It’s a common sounding from the selling parties on new or almost new homes. Especially those built without Tarion warranty. “Don’t worry, the City inspected it”. As an inspector serving the buying community, I am often amused by that statement. My income on new and nearly new home inspections relies directly on identifying the leftover issues after all the builder and municipal inspections are complete and the first owner has taken possession. These issues don’t go away on their own, and I also find “builder issues” on resale homes, even up to 50 years after original construction.

Don’t hesitate to have new or nearly-new homes inspected by a professional.

House Shopping 101: Infill “mansion” issues.

 

princess croppedby Keith Tripp, Revised 2020

Buying the infill “custom” mansion requires a bit of a different mindset than other homes. These homes are built in older, high demand urban areas, typically by smaller building and development companies. The old home is knocked down and a new one built on the lot. They are marketed as “custom”, but tend to be repeats of the same plans with minor differences in models. As with all new construction, there is some risk of incomplete or inadequate work, but a few areas stand out as being higher risk than buying from a subdivision developer. Here are the first few that come to mind:

 

 

 

 

  1. Age: For financial reasons, these homes are typically put on the market a year or more after completion of construction and have usually been sitting vacant or “lightly used” for that first year or more. The house is slightly aged but hasn’t been tested by actual occupancy. Appliance and other warranties may be expired. Because the house has been vacant or very lightly used, there is no assurance that everything is in working order. For example, it is common that not all of the bathrooms have been used on a regular basis.
  2. Warranty: For financial reasons, these homes are often built without Tarion warranty coverage, and the builder is not registered with the Ontario provincial warranty program called Tarion. Discuss this risk with your lawyer.
  3. Municipal and jurisdictional authority’s’ compliance: Permit approval is a multi-staged process. The fact that the house is for sale, or even proof of occupancy approval does mean that everything is complete and approved by the authority having jurisdiction. Due diligence is required to check completion and compliance of the building, plumbing, electrical and gas systems.
  4. Exterior claddings, especially EIFS: Details such as weep holes for brick veneer and drainage for EIFS are notoriously bad on these houses. I have yet to find one of these houses that does not have significant issues related to the exterior claddings. The use of non-draining EIFS (“stucco”) is common on these houses, and that practice has been known to be unsuitable for many years.
  5. Strange roofing slopes: High interior ceilings combined with height restrictions result in strange and unusual roof layouts. Typically, the top of the roof is flat, but the problem is that the slopes leading to the flat part of the roof are often too flat for normal shingle application. These roofs are not accessible with a 32ft. ladder. Very long ladders or lift trucks are required if any maintenance or repairs are required.
  6. Sump systems: Most of these houses have sump systems that are mandated by the local building department.  Footings may be lower than surrounding basements and often there is an exterior basement walkout drain connected to the sump.. Sump issues include: excessive water flow, incorrect use of perforated basins, illegal bypass of discharge piping to sanitary sewer, sumps in cold rooms that are subject to freezing, sump lids not meeting air barrier requirements, missing or poorly installed infeed pipes, perforated infeed pipes.
  7. Heat Recovery Ventilators not functional. HRV’s are often required as part of the Energy Compliance package to meet basic building code requirements. Issues include missing controls, missing electrical supply.
  8. Hydronic heating not labeled or commissioned: In-floor hydronic (using hot water pipes) heating, is good technology and is often installed in these homes. The issue is that the systems tend be completely unlabeled and without documentation. The hydronic heating is not typically required to meet the heating load of the house, so may not be included in the permit documents. These systems are sometimes completed after the inspection by the local Building Officials, so they are not inspected for compliance with code requirements or good practices.
  9. Roof flashings: Complicated roof designs means that the chance of incomplete metal work and flashings is higher.
  10. Unsafe decorative guarding ( rails at balconies and interior landings and stairways.) Climbable guard railings are not permitted in Ontario, however they are often found in the infill mansions in the form of decorative metal guarding. To pass municipal inspections, the guarding is covered with plexiglass during the inspection. Once the municipal inspection is complete, the plexiglass is removed, exposing the climbable elements.

If you are a home buyer in the GTA, feel free to contact me early in your house shopping process with the address and age of a house you are interested in. I can send you a few key questions to ask that may save you time and money.

Do I need a thermostatic mixing valve?

mixing b valveby Keith Tripp, 2020

A client recently contacted me with a question about mixing valves. The mixing valve installed at his house was acting up,and he wanted to know if it could just be removed or if it must be replaced. Mixing valves are part of a temperature control system for hot water. The intention is to reduce risk of scalding by keeping water that will contact humans at temps less than 49C (120F). This is especially important for children and the elderly.

Here is my response: Your question about the mixing valve has a few angles to consider. Bottom line, if you want to skip all the details below, is that I recommend installing a new thermostatic mixing valve.

 

There are 4 levels to look at . One is what year code applies to the house, the second is the details within the code, third is whether an issue would arise when selling or having a home inspection done, the fourth is the practical safety issue.

 

Starting with #4, as stated above, I recommend installing a new valve. Especially if the house is a rental property, or elderly people are using the house,  there could be liability issues by removing a valve that was originally installed for the purpose of temperature control. The valve also allows the tank temperature setting to be higher than 49C (120F). Some argue that this is necessary to reduce risk of Legionnaires disease, but that point is debatable. It does however allow for hotter than 49C water to supply a dishwasher or clothes washer if piping allows for that.

 

The code requirement: The key point is that the code ( even the current code)  does not specify a thermostatic mixing valve. However it  does specify the maximum temperature of hot water as 49C in 7.6.5.1. (See below) The thermostatic mixing valve has become the accepted method of controlling the temperature. You could argue that the water heater setting is controlling the temp, but in actual practice there are significant temperature swings in the supply temp. If you have a tankless heater with an electronic temp control, that may also meet the requirement without the mixing valve. Final decision on what code applies in each situation, and interpretation and enforcement of the code is the responsibility of the Building Official for your area.

 

What code applies? The code as is it is now with the temperature control  requirement I believe came into practice around 2004 , but not certain on that. The codes are not retroactive. Many houses do not have the mixing valve, and when water heaters are replaced in older houses, from what I see, in most cases a thermostatic mixing valve is not installed. This house originally had a mixing valve so safe to assume it was code-driven at the time of construction.

 

Will it be an issue when selling? Home inspections are based somewhat on code, but codes can only be interpreted and enforced by Building Officials. A missing mixing valve may or may not make it to a home inspection report. In my reports, I include presence or absence of the valve as part of the plumbing description, but not necessarily as an issue that requires attention.

 

See below the section of code ( current) that applies .You can find the code on line at :. https://www.ontario.ca/laws/regulation/120332

 

 

7.6.5.  Water Temperature Control

7.6.5.1.  Maximum Temperature of Hot Water

    (1)  Except as provided in Sentences (2) and 7.6.5.3.(1), the maximum temperature of hot water supplied by fittings to fixtures in a residential occupancy shall not exceed 49°C.

    (2)  Sentence (1) does not apply to hot water supplied to installed dishwashers or clothes washers.

7.6.5.2.  Showers

    (1)  Except as provided for in Sentences (2) and (3), all valves supplying fixed location shower heads, shall be individually pressure-balanced or thermostatic-mixing valves, conforming to ASME A112.18.1 / CSA B125.1, “Plumbing Supply Fittings”.

    (2)  An individually pressure-balanced or thermostatic-mixing valve shall not be required for showers if a single temperature water supply for such showers is controlled by a master thermostatic-mixing valve conforming to CSA B125.3, “Plumbing Fittings”.

Note: On January 1, 2020, Sentence 7.6.5.2.(2) of Division B of the Regulation is revoked and the following substituted: (See: O. Reg. 88/19, s. 181 (1))

    (2)  An individually pressure-balanced or thermostatic-mixing valve is not required for shower heads having a single tempered water supply that is controlled by an automatic compensating valve conforming to CSA B125.3, “Plumbing Fittings”.

    (3)  Deck-mounted, hand-held, flexible-hose spray attachments are exempt from the thermal shock requirements of Sentence (1).

Note: On January 1, 2020, Sentence 7.6.5.2.(3) of Division B of the Regulation is amended by striking out “Sentence (1)” at the end and substituting “Sentences (1) and (4)”. (See: O. Reg. 88/19, s. 181 (2))

    (4)  Pressure-balanced or thermostatic-mixing valves shall be,

(a)   designed so that the outlet temperature does not exceed 49°C, or

(b)   equipped with high-limit stops which shall be adjusted to a maximum hot water setting of 49°C.

Note: On January 1, 2020, Sentence 7.6.5.2.(4) of Division B of the Regulation is revoked and the following substituted: (See: O. Reg. 88/19, s. 181 (3))

(4)  Pressure-balanced, thermostatic-mixing or combination pressure-balanced and thermostatic-mixing type valves shall be,

(a)   capable of limiting thermal shock, and

(b)   designed so that the outlet temperature does not exceed 49°C or equipped with high-limit stops which shall be adjusted to a maximum hot water setting of 49°C.

House Shopping 101: Free info on houses for sale.

by Keith Tripp, 2020

To prepare quotes and to prepare for inspections, the more I know about the house, the better. Today you can have almost as much info as the real estate sales people, and at no cost. You should have this same level of info when house shopping and doing your own research.

As a home inspector, age of the house is extremely important. The age will determine risks related to older electrical and plumbing components, energy performance, and foundation (basement) leakage risk. The true age of the house is often not highlighted in the selling material. Age indicators include: street date (on the sewer caps, installation tags inside the house, window manufacture dates, HVAC equipment dates, type of construction, construction materials used and location. Always find out the year of construction of the OLDEST part of the house when house shopping.

Here are some of the (FREE!!!)  tools I use to get info on the property here in the Greater Toronto Area, Ontario, Canada.

  • Realtor.ca
  •  This is the public version of the MLS info. It does not show all the info the real estate sales people can see, for example names of  owners and age of house. Search by address on the map, or by listing number: shows house description and names of listing agent.
  • Bungol.ca : UPDATE: BUNGOL HAS BEEN SHUT DOWN SINCE AUGUST 5, 2020 I AM NOW USING HOUSE SIGMA, SEE BELOW.
  • This is the new kid on the block, arriving when laws were changed to allow for access to the MLS info. This is a powerful tool that real estate sales people wish did not exist. All of the info from realtor.ca except not the name of listing agent. The big plus with Bungol is it shows previous listing history such as terminations, price changes, and previous sales. It shows listing date and time on the market. It also shows when a conditional offer is in place and the expiry date of that condition. Age is shown but the range is quite broad.
  • HOUSESIGMA.COM  Similar to Bungol above. This is now my “go to”  site. It has bigger and better photos than realtor.ca. there is also an alert system that will email you when status of a listing changes.
  • Google maps:
  • Photos over previous years can show dates of exterior renovations and even date of construction for newer homes. Click on Street View and the option to look at photo view going back over the years. I can often determine the approximate date that a roof was redone, or significant changes to exterior cladding by looking at this feature.  Also good to look at  proximity to highways, bodies of water, railroad tracks, industrial areas.
  • mpac.ca:
  • MPAC is the Municipal Property Assessment Corporation. This organization does thee property assessments to determine property taxes. You can sign on by using the tax roll number of your existing property. Use the “About My Property : My Neighbourhood”  function to search the map. This is the best place to confirm year built, as the sales info likes to keep a low profile on that.  Also shows: Square Feet, Lot size, Number of storeys, Current Value Assessed, Sales Indicator (date of previous sales only back to 2012, not amount).

Plumbing drain traps and venting.

One goal of the home inspection is to identify non professional work. With plumbing work, much of the drain piping is not visible once the work is completed. The trap arrangement visible under sinks is often the only visible drain plumbing. If the trap is incorrectly done, this is an indicator of non professional work, and brings in to question all of the plumbing work. For a basement bathroom non professional work is a big deal because most of the drain plumbing is embedded in the concrete and cost to rework can be very high.

After the trap, drain pipes should flow at a low slope, typically about 1:50 slope, and a vent pipe should be attached within a set distance before the pipe drops sharply. On this drain, immediately after the trap, the pipe drops sharply. This can cause the trap water to be siphoned out, allowing sewer gasses in to the house. Risk is a bit lower because this drain is for a small sink in a powder room, typically not filled to the brim and then drained. The chrome pipe is probably about 60 years old and will basically crumble in your hand if you try to work with it. Time for some ABS work to make it OK.

Vent pipes are pipes connected to the drain system that allow air to enter the pipes. The pipes are routed through the house, and on Canadian homes they typically pass through the roof. Providing this connection to atmospheric air prevents siphoning empty of the traps. The traps (loop in the pipe) hold water that provides a seal against sewer gasses. This trap seal is essential to keeping sewer gasses out of the house.

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Drain pipe slopes too sharply after the trap.

House Shopping 101: Towards Maintenance-Free

by Keith Tripp, 2020

House Shopping 101: Towards Maintenance-Free. In this hustle and bustle world, maintenance is a dirty word. Houses are certainly heading towards maintenance-free as exterior cladding materials evolve, but some materials still have relatively short life. Here’s a few things to look at to assess maintenance requirements.

 

deck Picture1#3 Freshly stained decks are almost always rotten. Here in Toronto, Ontario, Canada, watch especially for decks installed on the South or South West sides of houses, where they catch a lot of sun and deteriorate faster. Even though most decks are built with pressure treated wood, the wood will rot at cut ends, or at nail holes or other locations where water is trapped. Often this wood  looks like new on the underside, so if boards have been screwed in place, one environmentally friendly option is to remove and turn the boards over and cut the rotted ends off. Decks over 15 years old with high sun exposure are likely to have rot and /or extensive splitting and splintering of the boards.

 

 

#2: Exterior wood and paint. Exterior wood can survive many years if it is installed in a position that allows it to drain. When ends of wood are butted so they trap water, or a horizontal surface is not sloped, the wood will rot. 10-12 years seems to be about the length of time for significant rot to occur at wood that is frequently wet. The North exposure may rot faster because of slow drying, and the South exposure may rot faster because the sun will accelerate paint deterioration. Most exterior panel boards are composite materials designed for exterior use, but real wood is still used as trim. Real wood was used on window frames through the 80s and 90s.

Painting may slow the rot, but will not prevent it on poor installations. When house shopping, even for brand new houses, watch out for wood that may require painting, especially in hard to reach places like dormers. It is common for me to find wood that is freshly painted and filled with sealants or other materials, but is completely rotted underneath.  Garage doors may contain real wood, and this is subject to rot, especially at the lower door panels. Door frames on balconies are high risk, as are porch columns.

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Rotted wood at window frames. 1996 construction,  Markham.

# 1: Exterior sealants (caulking). Life expectancy of sealants varies greatly based on quality of material, installation details, and exposure to the sun. Sealants on new houses will have the shortest life because wood shrinkage is causing movement. Sealants on new construction can separate within the first couple of years. More commonly though, failures in the form of separation will be noticed around the 7 to 10 yr age on the sunny side of the house, and 10-15 years on the less sunny sides.

The photo is at a 15 year old house, South facing window. In addition to the age and the South exposure, the gap at this junction was probably too wide for sealant, even before shrinkage of the wood frame. Sealant performance is specified based on maximum joint width . Backer rods ( foam material that acts as a filler in a wide joint) can be used, but there is still a maximum joint width recommended by the material manufacturer.

Flexible sealants have been used for many years. Newer materials exist that could displace the use of the sealants, such as gaskets that expand to take up movement, but they are not in use by the tract home builders.

sealant from word 70 lowther

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