HawthorneVillager.com

Hello,
I'm currently finishing my basement and am looking for some advice on insulating and vapour barriers. I have left the builder's insulation and vapour barrier there and built my 2 x 4 walls infront of it. I was going to put additional insulation between the studs which would be infront of the pre-existing insulation, and then put another vapour barrier, then drywall. However, a few weeks ago, someone else posted about this and now I know I shouldn't do double vapour barriers.
So my new plan was to put the insulation on top of the pre-existing insulation and vapour barrier and then drywall, but now I've also heard insulation against the drywall could create moisture too. What should I do?
Thanks in advance for your help!

Go to this web site and see insulation thats made here in Milton

Its waterproof, soundproof, fireproof thermal insulation made out of rocks...

www.roxul.com

You can put up a second vapour barrier but before you do, you will need to cut many vertical slits/cuts into the original vapour barrier. This way you will only have one vapour barrier.

_________________
For Home Inspection services call Andy Shaw at Halton Home Inspection Service. 905 876 4761

Some good info
http://www.gtahandyman.com/Basement_Renovations.html

John Allingham, Professional Engineer
Owner & Certified Home Inspector
Halton-Peel Home Inspection
(416) 254-5869
www.peelhomeinspection.com

I did exactly the same this year and I did what Halton Home Inspection has recommended to you. I built the studs up against the original insulation, and made huge slits from top to bottom right before I put in the new insulation...then new vapor barrier, then drywall. Do your studs first, so that you can slice and dice without risk of the insulation sheets falling off the wall and being a pain in the ass. If you light a match in my basement, you start sweating.

Another thing that I did that you might want to consider, is to reroute some of your heating registers down the walls and out at floor level. I find that it makes the floor much warmer, which is key for me beacue I have a small child who crawls around on the floor. This is super easy to do.

Good advice. I think this is required to meet code as well (at least that is what our inspector had told us). It allows for better airflow, and for me personally, I hate having hot air blowing down from the ceiling.

hey guys, I have a question. I might be visualizing incorrectly in my mind what you mean by placing studs in front of the existing insulation.

I haven't moved into my house yet, but am assuming the basement studs and insulation from the builder will only come down half way of the wall from the top. Wouldn't you just place your studs directly below what is already their and continue the bracing to the bottom of the floor, that way you are only having to add instulation to the lower half of the wall? That's how we did it in my old house.

Really confused by what you mean by in front of the existing insulation. Good thread though!

There are no studs in the basement. The builder does not need to (nor do they) build any walls for you down there. The builder insulates down the full length of the wall and wraps it in a 6 mill poly vapour barrier that is anchored to the concrete foundation wall.

When finishing the basement there are a number of ways you can handle the insulation as discussed here. Personally, I'm not a big fan of leaving any of the builder's junk around (personal experience in other areas makes me not like their "stuff" but that's just me). I'll likely rip it all down and put foam insulation against the foundation wall, then build my stud walls against that and then insulate using batt insulation. I'm also considering maybe getting it spray foamed instead (costly but beyond a doubt the best way to go). And when you spray foam you don't need to worry about vapour barrier.

thanks gecko, that completely clears that up. now i see what you guys are talking about. I never thought of foam against the foundation first and then studs and insulation, I like that idea, will have to remember that.

You can leave the builder's insulation if you want, but personally, for me anyway, it's nowhere near as good as what I would want to have in a finished basement.

Builder Insulation is R-8. I beleive R-14 is what most people would want to use in their basement. So they use the minimum code requirement but if you want a more comfortable basement, you would want a higher R-value.

Matt

I have a look out elevation, in my case over 50% of my back wall is above grade.

Most people have about a foot above grade that is only at R-8.

For a few hundred dollars, it may be worth adding more insulation now, then regretting it later on with drywall up and the room finished. You may need a space heater as well which would cost more in the long run.

I too am flip flopping on what I want to do but you do raise a valid question. Hopefully someone else has some good insight to that.

Matt

We just recently finished our basement and installed the roxul safe n'sound around walls that had rooms that were more noisey (ie washroom, furnace room, our laundry room is in the basement) and used pink fiberglass on all other walls, even interior (r-12 i believe). I could not be happier with the result!

One note though, the roxul is ALOT easier and managable to install and i would put that everywhere if i were to do it again...but would of cost about $800 more (the pink was on at a really good price at the time)

Greg

I did exactly the same thing in my previous house and we were happy with the results.

Now, I have a lookout lot and most of my back walls are well above grade. R-8 doesn't quite cut it, at least not for me. I agree that maybe it's partly a matter of personal opinion but there is no way I'm going to err on the cheap side when finishing my basement because the downside is too great. We're only talking about a few hundred bucks. In the grand scheme of finishing your basement, it's nothing.

#1: Builders often squish the R8 basement stuff when they install it, which drops the R value significantly

#2: R12 is definitely sufficient in basements, when properly installed with vapour barrier.

#3: if you choose to leave the builders stuff up, you'll lose a couple of inches of room space on each side, no big deal to some, but a big deal to others. So the easiest install with less going to the dump is to leave the builder stuff up, build the walls in front (you can squish it a little because of the next steps), cut slits in the existing vapour barrier as mentioned above), then put in pink R12, and 6mil plastic on top. (cost effective, less waste)
Dont forget to use vapour proof covers for your electrical boxes on that wall, and don't cheap out on the Tuck tape.

An incorrect install will really kill the benefits of the job - Ask pros for help (of which I am not! lol

It is not an expensive job when looking at the whole project - if your basement isn't warm and dry, you won't want to go down there as much!