Category Archives: Insulation


A vent that exhausts moist air to the home’s exterior has a number of requirements:

  1. It should be connected. The connection is usually behind the dryer but may be beneath it. Look carefully to make sure it’s actually connected.
  2. It should not be restricted. Dryer vents are often made from flexible plastic or metal duct, which may be easily kinked or crushed where they exit the dryer and enter the wall or floor. This is often a problem since dryers tend to be tucked away into small areas with little room to work. Vent elbows are available which is designed to turn 90° in a limited space without restricting the flow of exhaust air.  Airflow restrictions are a potential fire hazard.
  3. One of the reasons that restrictions are a potential fire hazard is that, along with water vapor evaporated out of wet clothes, the exhaust stream carries lint – highly flammable particles of clothing made of cotton and polyester. Lint can accumulate in an exhaust duct, reducing the dryer’s ability to expel heated water vapor, which then accumulates as heat energy within the machine. As the dryer overheats, mechanical failures can trigger sparks, which can cause lint trapped in the dryer vent to burst into flames. Fires generally originate within the dryer but spread by escaping through the ventilation duct, incinerating trapped lint, and following its path into the building wall.


If your home is missing foundation vents, I recommend having a qualified contractor come out and evaluate/install foundation vents around the perimeter of the home to ensure that the foundation and underside of the home are properly cross-ventilated.  Ventilation is CRITICAL to homes in the Pacific NW; lack of ventilation can lead to myriad issues including, but not limited to, attracting wood destroying insect (i.e., carpenter ants, termites and anobiid beetles) and mold.  Truth be told, mold is VERY RARE in crawl spaces under homes, but insect activity is not.  So, keep the underside of the home well ventilated and they’ll have no interest in your home.  It’s all about moisture!  If it’s impractical to cut in or install foundation vents, a mechanical vent fan on a humidistat can be easily installed.  Personally, I prefer foundation vents because they don’t rely on electricity or anything fancy to operate.  Keep them open and let Mother Nature keep your home’s crawl space ventilated!    


Have lint accumulation at exterior dryer vents cleaned/cleared away.  Not only is it unsightly, but it prevents proper ventilation of the dryer appliance within the home.  

It’s super easy to clean exterior dryer vents.  Here’s a link I found online with some great tips and advice.  Here’s how to clean your dryer vent in 5 easy steps – CNET


Like a fine wine from the Columbia Valley, your home needs to breathe. 

For example, soffit vents around the perimeter of a home can help with attic ventilation issues. However, too much ventilation is not a good thing.

I recently inspected a home in Anacortes that was missing soffit vent screens around the perimeter of the building. When vents are not screened, birds and other animals may decide to put down stakes in your home. 

Not exactly something to say “cheers” about. 

If you have questions or comments about ventilation issues or home inspections in general, tweet me (@AIHomeInspect).


Although pink is arguably one of the best colors, it’s not the best to have exposed pink foam board insulation in your attic or crawlspace areas for safety reasons.  I recommend that you cover exposed pink foam board in your attic/crawlspace with a noncombustible material, or remove it if that’s impractical. 

Exposed pink foam board insulation is combustible and could catch fire and creep up on unwary dwellers.  Either take that stuff out, or get it covered!

Having pink foam board insulation in your attic or crawlspace does not mean that your home will undoubtably at some point catch fire.  But because the possibility remains, I recommend you remove or cover pink foam board insulation.  


Every month, we seek to bring our readers insight from the worlds of home construction, home repair, and home maintenance straight from local Northwest Washington contractors in a segment we call “3 Questions.” Yep, you guessed it: we ask three questions, and the contractors answer them.

This month, we learn about insulation issues with Brea Mason at Pacific Rim Insulation Inc. in Friday Harbor. 

Q1: Attic insulation is priority No. 1 for homes (hot air rises after all!).  There are lots of options for insulating attics (e.g., spray foam, blown-in fiberglass/cellulose, batten insulation, etc.).  Can you please let us know some pros and cons in material choices and overall advice for insulating attics?

There are many different choices for insulating your attic spaces. If you have an existing house, with a nice clean attic and are looking to increase your insulation,  I really like to use blown-in fiberglass insulation. It fills in all the gaps and cracks you may have and sets down a nice blanket to cover it all up.  I think getting an attic to an R50/R60  provides great resistance from the outside elements in our area. On new homes you have many options, but we have been installing closed cell foam with batt insulation combo in quite a few homes. It makes your roof a non-vented system, so no worries that you don’t have enough air-flow behind your insulation. 

Q2: What’s your favorite type of insulation and why?

My favorite type of insulation would be rockwool, or closed cell foam. Rockwool is so versatile, good for sound, gives you an R23 on exterior walls, is fire protectant, and is an overall very dense product—which means better resistance (or R-value). Closed cell foam is my other favorite because of the sealing power it has as well as its high R-value per inch (R6.9 per inch). On  older houses with 2×4 exterior walls you get an R21 and 11 percent sheer power, so that is a win-win.

Q3: An amazing statistic is that up to 30% of heated air can be lost through a ceiling attic access hatch that isn’t insulated and weather-stripped.  Do you have any high-impact recommendations homeowners can employ to improve thermal efficiency and save money?

I think a lot of people don’t know if their access hatch has any insulation on it at all. We always build a dam of insulation around the hatch and then install insulation to the back side of the access cover. You can hold the insulation with twine or you can cut a piece of rigid insulation and glue it to the back of the hatch. Weather stripping is so important! Around light can covers, electrical outlets and attic access hatches. We are always trying to stop the air from infiltrating.


Whenever I see messy crawl spaces, I let clients know to clean things up. 

But wait, Tim, aren’t all crawl spaces messy? And why is that important?

Well, yes, all crawl spaces are messy to a degree. But not all crawl spaces contain debris that I’d consider conducive to environments that promote wood-destroying organism activity. These are truly messy crawl spaces!

When I see materials like cellulose, cardboard, and wood laying around underneath a home, I always recommend their removal to let wood-destroying organisms know they are not welcome.

Bugs, be gone!

During a recent inspection on Fidalgo Island, I noted this type of debris in the form of concrete cardboard forms. 

If you have questions or comments about crawl spaces or home inspections in general, tweet me (@AIHomeInspect).


Foundation/crawlspace vents have covers that really should be removed entirely for proper ventilation.  In fact, I strongly advocate against installing vent covers at all.  Ventilation is absolutely critical to maintaining proper humidity levels in the crawl space under the home and to prevent moisture and insect damage.  

I recommend keeping crawl space vents open all year, provided the water supply pipes in the crawl space are properly insulated.  For more information on foundation/crawlspace vents please check out this YouTube video I made several years ago on the topic:


Asbestos is an issue that often comes up when inspecting older homes, even homes that have been “completely renovated.”  Textured “popcorn” ceilings, ceiling tiles, floor tiles, vinyl flooring, roofing materials, insulation, and white tape wrap on pipes and furnace ducting commonly contain asbestos.  

In fact (news flash!), did you know that even modern homes could contain asbestos? Asbestos isn’t typically a health concern unless it becomes disturbed or starts falling apart. In the industry, the term “friable” is often employed, which means “easily crumbled.” 

If you suspect asbestos in your home—and it appears “friable” or could in any way become compromised—it could very well be a safety issue worth investigating for safety and liability reasons.  

If you’re planning to renovate a home- even a newer home- testing materials to be disturbed or removed for asbestos is advised by professionals.  Confirming asbestos requires laboratory analysis, which is not very expensive. Visit the Environmental Protection Agency website to learn more about asbestos in homes.

If you have questions or comments about asbestos issues or home inspections in general, tweet me (@AIHomeInspect).


If it seems I write a lot about moisture-related issues, then you’ve been paying attention. Moisture is Enemy No. 1 for homeowners, whether natural or man-made.

Today, I’d like to address an (unfortunately) very common man-made moisture issue that I see on a regular basis: bathroom vent fan ducting that discharges directly into the attic. I was just in a home on Orcas Island where I encountered this issue. I had a strong suspicion that this lack of ventilation was creating an environment where apparent mold-like growth I noted could thrive on plywood sheathing.

If you have questions or comments about ventilation issues or home inspections in general, tweet me (@AIHomeInspect).