Protecting a home from rain may seem like a straightforward practice for builders in Oregon. Yet we’ve seen that, too often, something can go wrong. We want to share the importance of understanding some potential failure points so homeowners and architects can choose a builder who has quality practices in place.
Building inspections do not systematically address the building envelope
The building envelope, which is defined as the entire exterior section including the walls, windows, and roof, that separate the outside of a property from the inside. The building envelope not only keeps outdoor elements like rain, snow, and dust from coming indoors, but it also helps maintain a constant room temperature. But very few building codes and inspections focus on the details of the building envelope. In the Portland area, there is a code that requires properties to have a rain-screen, which is the breathing space between the weather-resistant barriers (WRB) and the siding; however, during construction, an inspection is not mandatory to ensure that a rain-screen is in place. As a result, it’s important to choose a builder that follows all the requirements and best practices.
It takes one mistake and you’re chasing a water issue
Here’s one painful example. You, the homeowner, have chosen a top-quality membrane material for your new modern flat-roof house. You’ve been told how the seams will be expertly ironed together, and your architect has placed a slight slope onto your flat roof to correctly drain water off. So far, this is all good. However, it only takes one tiny prick in the membrane by the roof installer, and you will be chasing that leak across your home. That leak will likely not “appear” near where the culprit hole. It can be quite the chase.
In the design and build industry, it’s also common to see installers work their way from the top to the bottom using an exterior weather-resistant barrier (WRB), typically with Tyvek. WRB is highly susceptible to capturing moisture in the air and thus, creating unwanted leakage.
There’s also a way that flashing can be installed that, with just the right conditions, like the wind direction and barometric pressure being just right, can create a leak and then only leak under these conditions. It becomes very difficult to recreate where the leak came from.
Most standard residential builders in this industry have the windows installed by one trade partner, and the exterior sheathing, siding, weather-resistant barrier, caulking, and flashing installed by another trade partner. Some may even have a third or fourth trade partner install the roofing. Having several trade partners work on one residential home can pose several issues for clients. Problems can be avoided by choosing a builder that has a long standing and trustworthy relationship with one trade partner who is responsible for constructing the entire building envelope. Thus, if the job is not done correctly, it is much easier to pin-point the source and find a solution quickly.
Having a contractor who keeps up with building science helps
Older homes have a natural airflow, so that when moisture was built up, there is circulation for the moisture to dry up. But these homes have their leaks, and so our building science has come a long way. In today’s home, it is so buttoned up and tight that we need to add in extra breathing material. This is just one example of how things have changed in the way we build. There continues to be improvements to make homes more durable. We believe that a quality contractor pays attention to all these changes. Every time there’s one change it can affect other aspects to the home.
Remodels and opening up the building envelope must be done with care
If you add a skylight, a dormer, or a new space, there needs more planning for protecting the rest of the home. Ideally, you open up your home in July through October. Some projects can only be done during these months, because the cost would be too prohibitive during the wetter season.
In an ideal world, you don’t ever touch your building envelope, but it can be done, at least with solid builder expertise. For example, if you want a skylight, you need someone who understands how far back to take the roofing and how to handle the flashing. It’s also better not to piecemeal your remodel into stages such as adding a second story addition after your new kitchen was recently finished. It just costs more money and time to protect the rest of your home.
What our clients are building for better living during the rainy season
If you are thinking about a home project, consider breezeways or patios that you can use 10 months out of the year, and that are possibly heated. We’ve had a number of clients request these outdoor spaces, especially since the pandemic. Also, we have noticed what a difference bigger windows and skylights can make for bringing natural light into a home, which can be so important during our darker and wetter months. Overhang roofs are also appealing both as a place to sit outside and for keeping the water off of the home.
We would be happy to talk with you about your project
At Hamish Murray Construction Inc., we pride ourselves in knowing not just how to build a quality home or remodel, but how to build on schedule and on budget. We would be delighted to talk with you about your project ideas. As builders with many years of experience, we work with the designer or architect of your choice to bring your dream home to life, while keeping your project within a realistic budget. Contact us or call us at 503-460-7203 to tell us about your remodeling plans. We look forward to working with you!