m2244

Hello,

I am in the process of remodeling our 90-yr-old house. One problem we have is that the walls only have about 3 inches of blown in insulation. On the second floor we have a wall on each side of the house that has a vented crawl space (it's larger than a crawl space. Gambrel roof). So what they did was staple cardboard to the back side of the studs and then blow the insulation in. I would like to put another layer of insulation hopefully without firring the studs out.

How could I do this? I was thinking about some sort of rigid board but I am not sure.

drewdin

Any pictures?

nealtw

Foam board may create a problem with vapour barier on both sides of the wall.

m2244

Sorry, if I crawled in there nd took a pic, it would just look like a cardboard wall.

kok328

Foam board does not make for good insulation. I believe a 2" foam board yields about an R-3 value.

nealtw

R-5 per inch

Perry525

The most effective place for insulation is on the warm side of a wall.

Putting the insulation on the cold side, means you are paying to heat the frame and the spaces between the sticks. (and this means tons of wood, soaking up your heat)

An inch or two of closed cell insulation like polystyrene will make a very big difference to how warm and cosy you feel.

Putting the insulation on the inside means you can work at night, it won't matter if it rains or snows. Best of all you have room to move and you can stop and start whenever.

The insulation you have at the moment is almost useless, being open cell the air and heat pass right through it - the only time it works well, is when its placed in an airtight bag.

Wuzzat?

You may want to rent or buy an IR meter or take photos with a filter that allows the infrared to pass, to find cold spots that need the most work.

Fireguy5674

Another option might be to remove the cardboard and existing insulation then spray a two part insulating foam over the back side of the wall. Depending on the age and condition of the insulation it might be better to replace it anyway. You can make the insulation as thick as you would like because you are not limited by the depth of the wall cavities. The spray on insulation not only insulates but does a better job of sealing any cracks or small spaces that allow air leakage. If you are working on a 90 year old house you know what I mean about filling those kinds of voids. You can buy kits for DIY projects or hire an insulation contractor. Do a search for 2 part insulation foam on the internet. There are lots of options available there.