Choice of building materials should reflect humidity conditions

Hey there, time traveller!
This article was published 01/08/2015 (3756 days ago), so information in it may no longer be current.

Question: I enjoyed an article you wrote about dealing with moisture issues in a cottage crawl space. My question is from a different angle. I’m looking to build a “baby boomer” cottage, one level, and have been reading on the type of foundation and building materials to use. The area is on the ocean, Bay of Fundy, N.S.. The cottage would initially be seasonal. Is it better to run utilities during the winter, instead of draining the pipes? What is your experience on this? My concern is it being too weather tight and unable to breathe if it is closed up. I’m also looking at whether it should be stick built versus using structural insulated panels. Do you have any advice for the foundation or any other materials that would work?

Thanks, Karen D.

Answer:

Choosing to build a traditional summer cottage may not be the option it was several decades ago. Because of stricter adherence to building codes, this may not be possible, depending on local authorities. Deciding on specific building materials is always a challenge when building new, but exploring local requirements and experience from local building professionals will be a must, to truly know the best options.

Despite your desire to plan your baby boomer ocean-side home for mainly summer use, it will still likely have to be built for year-round use. For many decades, small communities and other areas throughout Canada have allowed summer use cottages, cabins, or camps to be built without taking harsh winter habitation into consideration.

Thousands of these older summer residences still exist, but are slowly disappearing. Many areas in most provinces are requiring all newly built structures to adhere to the minimum requirements of the National Building Code (NBC). This includes thermal windows, proper insulation and air/vapour barriers, and a functional heating system. Because of this, some material choices may be limited to traditional materials such as OSB or plywood sheathing for the roof and wall sheathing and batt insulation with polyethylene for the walls. More modern blown-in foam insulation may be used, but will be much more costly.

My experience with building in a very humid environment is limited to numerous lakes in Manitoba and Northwestern Ontario which, other than the saltwater, should have conditions similar to your location. I have only visited the Bay of Fundy area a couple of times, but have stayed in properties with similar ocean-front locations on those occasions. The summer/fall climate does remind me of many lakes in this area, but I’m sure winters are somewhat warmer and much wetter than on the prairies. For this reason, the choice of building materials should certainly reflect the high humidity conditions.

Traditionally, in many waterfront locations, wood-clad structures were chosen for many reasons. While they required regular painting and maintenance, they performed well for decades.

The natural properties of many types of softwoods allow them to readily absorb moisture, but also release it and dry quickly, preventing damage. Woods like cedar and Douglas fir, which have natural resistance to rot, have always been a good choice for seasonal homes. Unfortunately, the availability and cost of these materials can be limiting and you may want to look at manufactured products for some of these components. Siding and exterior trim, which can take the brunt of the harsh weather conditions, should be especially durable. Cement composition siding, or less-costly vinyl siding, will be very weather-resistant choices to combat the humid conditions. They both are also very low maintenance, compared to other natural siding materials, allowing you to spend your leisure time enjoying your summer home rather than constantly painting.

The type of foundation and framing materials used will largely depend on the interpretation of the NBC by the local building officials. Checking with the municipality where your new building is located to find out these requirements before obtaining building permits should yield some of your desired answers. If the area is primarily surface bedrock, foundations may be simple. If the area has poorer quality soil, or sandy soil conditions, a more elaborate foundation may be required. Poured concrete piers, driven piles, or concrete footings may be needed to prevent serious building movement. This is very important on ocean-front properties, especially if the lot has a substantial slope.

My observations from your part of the globe are that these are very realistic possibilities. As far as the choice between framing the building one board at a time versus manufactured trusses and components will depend on numerous factors such as access, cost and availability.

My own summer home is fully insulated and heated for year-round use, but we choose to drain the pipes and turn the heat off most winters. That is due to the limited number of times were use it in the winter, so it does not make sense to waste the energy and money just to keep the pipes from freezing.

Most municipalities will require you to build to modern standards and the NBC, including a proper foundation and insulation. Checking with local authorities, before you finalize your plans, may save you a good deal of frustration, once those choices are made.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the past president of the Canadian Association of Home & Property Inspectors — Manitoba (cahpi.mb.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.

trainedeye@iname.com