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Bryan Baeumler: Look behind your walls

Most homeowners don’t think twice about what’s behind their walls. But they should. Because there’s always the chance — however small — of finding hidden treasure. And also because proper insulation is vital to keeping your family safe and comfortable.

You need to understand what’s padding your walls, especially if you live in an older home and renovating the attic is on your spring to-do list. Not only is it key to keeping your house warm in the winter and cool in the summer, it’ll prevent mould from growing and can drastically reduce your energy bills.

Yo B’dog — ’sup? I’m renovating a basement bathroom and have gutted it down to the studs; the walls are insulated on the top half. The basement is partially finished so I was wondering: On the finished half, is it feasible to take out a four-foot section of drywall down the middle of the wall, remove all the fibreglass insulation behind to the underside of the first floor and then sprayfoam top to bottom? Thanks in advance.
Rob V., Mississauga
 
’Sup yourself, Rob? I’ll be totally honest: it’ll be tough to remove just a portion of the drywall. The best thing to do is pull that drywall off, pull that insulation out of there and spray foam the entire cavity from top to bottom, right against the concrete. That eliminates airspace; it’ll seal the wall and seal the air.

While you’re at this stage now, you might as well just open it up to inspect the house’s concrete foundation. Make sure there are no big cracks or any structural issues. That’s my best recommendation.

I think trying to pull down half the drywall, realistically, might save you a few sheets but will result in a lot more taping and fiddling around to try and fill in a four-foot section halfway around the room. It could be more trouble than it’s worth.

I’ve read that insulation can be injected into stud walls that are already sheetrocked. My house has no insulation or vapour barrier on the exterior walls; it was built in late ’50s. Is this technology cost-effective, or would you recommend removing and replacing drywall?
Harv O., Oshawa, Ont.

Harv, this is an easy one for me. We’ve opened up a lot of walls in older homes. Typically, in a house built in the ’50s, you’re only going to have about an inch of space in between the plaster and the bricks. Adding that little amount of insulation is really negligible. You need at least an inch to just vapour- and air-seal a wall.
The other problem is, the walls aren’t perfectly smooth and flat —there’s wiring, bits of wood, blocking, bracing and all sorts of stuff. So when you inject that foam in there, it may hit a wire or piece of wood and stay where it is without full and complete coverage. So there’s no way to effectively retrofit that insulation. Personally, I don’t think you’ll get a return on your investment.

The best thing, by far, to do is open up those walls, frame them out properly so you can spray in at least an R20 in that wall cavity, and seal the house. You’ll notice a remarkable reduction in your heating and cooling costs.

Bryan: We had our ensuite bathroom renovated to add a shower. But the drain in the shower makes a loud gurgle when we flush the toilet — is this normal? We tried the plunger over the drain and then noticed the water in the toilet moved, so we think there is something wrong with this set-up! We have also had a large number of little black bugs.The man who did the work seems to think that it is perfectly OK.
Helen D., Orono, Ont.

Helen, it doesn’t sound OK. It sounds to me like there could be two issues here: 1) the shower drain isn’t vented properly or 2) there’s an improper slope on the drains. Typically, when you flush the toilet, you shouldn’t hear it gurgling in the shower. That means the water going down the toilet is creating a vacuum that’s sucking air through the P-trap of the shower. That’s not good. If you don’t use the shower a lot, there should be a trap seal primer in there to keep that P-trap full of water, so there’s no sewer gas coming up. That would be my concern there.
You mentioned the man who did the work thinks it’s OK — I hope you mean the licensed plumber and, if not, I suggest you call a licensed plumber to inspect the drains. He could put a scope down there and see exactly what’s going on. Or open up a portion of the drywall and find out if the slope is incorrect or if it wasn’t vented properly.
When it comes to the bugs, those are typically called drain flies. They live and breed in the organic matter inside moist drains. You should clean the drains out with some organic material remover, like Drano. Then pour some water through the drains to empty the P-trap. Use a pipe brush and push it into the pipe to scrub the insides of it.

Hi, Bryan. I love your shows. Our master bedroom walls have separated from the ceiling at the joint. This first happened when we had the extreme cold last year. In the summer it is hardly visible. What time of year should this be repaired? Would it split again when it gets really cold? Is there something else we should be looking at — maybe insulating the attic?

Well, Mary, these types of cracks are very common in the winter. Generally, houses move a lot. When it’s cold, the air is very dry, which sucks the moisture out of the lumber and framing in your home, and all the lumber will shrink and that lumber pulls things apart.
 
Getting up into the attic and adding some insulation is never a bad idea, just to keep some of that warmth in the house. You could also make sure you’ve got a humidifier installed on your furnace. Typically, you want 40-45 per cent humidity in your home, to keep moisture in the air so that your house doesn’t shrink as much.
 
If the cracks are there in the winter, I’d suggest putting a paintable caulking, like DAP, to fill the crack and use a moist sponge to wipe over it and make it invisible. If you don’t control the moisture and add insulation to the attic, the problem will just keep reoccurring every winter.

Hi, Bryan: Love your shows! Problem: 60-year-old, back-split house. Living room, dining room and kitchen are over a crawl space. With the very cold winters these past two years, it is hard to keep these spaces warm. Can the furnace pipe that goes through this space be insulated? Also: the walls of the house are brick, tar paper and plaster — no insulation, and not willing to take them all down. What would you suggest?
Dolores M., Etobicoke, Ont.

Well, Dolores, how about selling your house and buying another that’s built properly. I’m kidding — kind of.
There are only two ways to insulate: either from the inside or the outside. If you’re not willing to take all the walls down, consider an exterior insulation and finishing system — a type of foam for the outside of the house that you can then put stucco, siding, brick or anything on top of it. You can basically insulate your house from the outside.
With the crawlspace, any heat vents that travel through this area have to be insulated so they’re don’t lose the heat as they come into those rooms. The other way to do it is to actually insulate the exterior walls and floor of that crawlspace, and have a heat run blowing hot air into that crawlspace to make it a warm zone. That will significantly warm up the floors in those other rooms.

The problem you’re dealing with here is you don’t have any insulation anywhere in the house. So even warming up the floors will do something, but it won’t make a massive difference to the house.

My recommendation would be to have an HVAC pro come in to make sure those vents coming through the crawlspace are insulated. You can also do an airflow test on the vents in each room to make sure there’s enough air actually getting to those rooms. With old, leaky pipes, you could be losing air pressure or the rooms closer to the furnace will be getting more airflow than those further away. But I would also definitely look at insulating that crawlspace, getting an HVAC pro to install a heat run in there and make sure that space is warm underneath the floors.

Mary V., Milton, Ont.

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