Spray Foam For -15 Days

Winter is kicking the crap out of us. And it’s everything our energy-efficient house can do to keep up. School is cancelled tomorrow because the high is supposed to be around 4 degrees, and lows around -15 degrees.

A weak in our super insulated house that I noticed recently is down in the basement. There are a series of penetrations in the rim joist where various mechanical systems go outside. These include holes for a spigot, the fresh air energy exchanger and what I think is the septic tank.

When they built the house nearly three years ago, the insulation was sprayed first, then the plumber and HVAC guys came in to set up their systems. Well when they did their job, they cut away the insulation but never bothered to spray foam around the pipes. Thus creating a kink in our insulating armor.

Recently when we had the spigot replaced (twice), due to leakage, more foam was removed from that particular hole and not replaced.

When I was finishing off the basement shelves this winter, I noticed I could see cobwebs near the holes blowing in the wind. Air was rushing into the house through the uninsulated penetrations. Because the house is super tight (or is supposed to be), any air penetration is exaggerated. So it was like little jet streams of air pouring in, and recently 0 degree air.

I was going to wait until the weather warmed up to spray some foam into the openings. I’m not sure if the cold air will affect the curing of the foam, as it hardens into an air tight barrier. But with -15 facing us tomorrow I figured I’d better spray today.

I used one can, and sprayed around all the openings. The foam takes a while to expand and harden, so I’ll check progress in the morning, and likely pick up another can to spray. There were a couple other little areas, like where a HVAC register is smack dab against the rim joist, that could use some foam.

When spraying, take your time. These areas are really tight to access, and a flashlight is necessary to be able to see. And don’t be like me: wear gloves. I got the nasty stuff on my hands and in the fur on my arms. It does not come off!

Overall the house has been holding up to winter in terms of keeping us warm. My office area is fairly cold and I’ve taken to plugging in a space heater. I’m also getting old and can’t seem to shake the cold anymore. We’ve been using the pellet fireplace a lot more this winter too. It works like a dream. One other note, the passive solar part of our home building equation definitely works. The kitchen, dining, family room area gets unto 75+ degrees on sunlight alone, which presumably takes some load off of the HVAC system.

I hope you’re all staying as warm as you can. I’m really depressed with the weather we’re having and can not wait for spring to get here as soon as possible.

Here are today’s pics. Peace.

Spray foam comes in a can. It's one time use, so use the whole can.

Spray foam comes in a can. It’s one time use, so use the whole can.

Pipes for the geothermal or septic system. Really tight access to where they penetrate the rim joist.

Pipes for the geothermal or septic system. Really tight access to where they penetrate the rim joist.

The input or output, I forget, for the fresh air heat exchanger. Fairly good access. Note, the laundry room HVAC vent in the adjacent bay is right against the rim joist, and could benefit from some spray foam.

The input or output, I forget, for the fresh air heat exchanger. Fairly good access. Note, the laundry room HVAC vent in the adjacent bay is right against the rim joist, and could benefit from some spray foam.

spray-foam-around-house-penetrations

Basement Project – Insulation

In the past basement insulation was often overlooked. Typically basement walls were cinder blocks and that was it. Now there are so many options from a construction standpoint, you really need to do your homework to see what suits your home building situation. Layer on top of that all the options there are for insulating your basement, and you’ve got your work cut out for you.

Insulating your basement goes a long way to reducing your energy bills, and increasing the comfort of the occupants living inside the home. Even if your basement is a storage catch-all, or a place to sequester unruly family members, there is great value in making your basement warm through the use of insulation.

The main advantage basements have, compared to the rest of the house, is it’s surrounded by soil. And the deeper you go, the more the temperature of the soil levels off around 50-60 degrees. Even at 4′, the temperature starts to hold its own verses air temperature above.

Here is a cross-section of our basement, provided by the wonderful peeps at Ferut Architecture:

Basement wall section courtesy of Ferut Architects. copyright 2014

Basement wall section courtesy of Ferut Architects. copyright 2014

So, taking a look at the diagram, you can see our awesome Superior walls make up our foundation. They’re awesome because they are prefabricated cement and include R-15 of rigid insulation right from the factory. Check out  this post to see how they were installed. It was amazing.

The plan was to add 3″ of sprayed 2 pound insulation to the inside of the Superior walls; adding R-20 to our R-15 walls for a phenomenal R-35 insulation rating to our basement walls. Also note we already have R-20 (4″ of rigid) under the cement floor. The basement would be warm snuggly nest once we were done.

Basement before insulation.

Basement before insulation.

Well turns out due to cost restraints we needed to dial it back a bit. What we did was in all of the areas that were getting drywalled, we had our friends at R-Tek Insulation in sunny Barberton, Ohio, spray 1.5 inches of insulation on just the top 4′ of the 10′ walls. This gives that area an added R-10 of insulation, for a total of R-25. This is better than most foundations, and worlds apart from traditional uninsulated cinder block walls.

The spray foam provides an air tight and presumably water tight, or at least water-resistant seal on the walls. Once the drywall is on, our basement should prove to be more air tight. The combination of air tightness and increased insulation should lower our HERS rating from its current level at 41. I’m not sure if I’ll get the house tested again. Maybe down the road after I do a few other things (to be determined).

By the way, spray insulation must be covered with sheet rock (drywall) as I do think there are fire concerns with the material when it’s simply exposed. We limited our spray only to those areas where there would be drywall. The storage rooms did not get any additional insulation at this time.

For reference on a scale from 0-150 the average home has a HERS rating of 130. New homes have to have a 100 rating. A zero energy house (which we hope to be someday) is 0. Our house is about 59% more efficient than your typical new house.

The cost for our additional insulation was $2,000. To do the entire top to bottom at R-20 would have likely been $8,000 or more.

Basement after insulation.

Basement after insulation.

The white colored spray foam expands as it dries. It also creates a air tight, water tight barrier.

The white colored spray foam expands as it dries. It also creates a air tight, water tight barrier.

The top 4' are insulated with 1.5" of 2lb. spray insulation (R-10).

The top 4′ are insulated with 1.5″ of 2lb. spray insulation (R-10).

Another option instead of spray insulation would be adding more polystyrene rigid insulation. Check out the Superior website here, for more information. You simply cut and install the rigid, bonding it to the existing rigid in the walls using liquid nails or other non-foam attacking adhesive. In fact this is what I will do for the storage rooms where we won’t have drywall. Because the spray insulation needs to be covered, per code, putting rigid in the storage rooms is my only option really. So strangely enough we will likely get a full R-20 floor to ceiling in the storage rooms because I just have to pay for material. It’s a super simple DIY job that I can do myself – free labor! Actually in hind sight, I should have likely done this everywhere from the get go, but I already had the insulation guys lined up. No worries, I like the spray insulation. And down the road if we really want to I’m sure we can go back in to the exterior walls and spray more (would have to replace drywall though).

One other note, I don’t think you ever want spray paper based insulation in your basement. With all the potential natural moisture issues, like the potential for flooding, in a basement, paper based insulation (like we have upstairs) is a bad idea.

There you have it. Now onto finishing framing and building some storage shelves.

Let me know if you have any questions or comments below.