Insulating behind drywall already hung

[euspaoc]

Hi,
I am looking to convert a 23'x22' attached garage into a home theater room (we're building a detached garage as well). The room has drywall hung and is textured. Two of the walls do not have insulation behind them (exterior walls are wood based).

Rather than rip out the drywall and install insulation and then re-hang the drywall/texture etc., what options are there? Cut holes in between each stud at the top and "blow" insulation in? The attic already has blown insulation in it. Thanks for your help.
Patrick

[Wgoodrich]

You probably have the best idea. Buy Celulous fiber insulation by the bag, rent a blower from that supplier and drill a hole big enough to allow the hose to enter the wall and slide down the wall space in each wall space. Make this hold more like cutting a strip of drywall about 1 foot high all along the top of the wall. Then you can buy a sheet of drywall and cut it into many strips that will fill it back in later and tape and bed then paint. Reason for the entire stud space to be opened about 1' is to allow you to shove you blower hose down the wall and watch it fiil up knowing it filled without bridging gaps allowing air leaks.

Make sure you do not have knob and tube wiring in those walls. Knob and tube wiring is not allowed buried in insulation.

Good Luck

Wg

[Shroomer]

While not a DIY suggestion... Spray foam is a very good alternative. It can be used as you have suggested, but I think it takes 2 holes insted of 1.

[mdshunk]

While not a DIY suggestion... Spray foam is a very good alternative. It can be used as you have suggested, but I think it takes 2 holes insted of 1.

I saw a guy do this in an older, plastered home. He got some spray foam that came in big bar-b-que grill propane tank sized tanks. The next day, almost every wall cavity swelled and popped and cracked almost every square inch of plaster. If this wasn't such a pitiful sight, I would have laughed my rear end off. There must be a trick to this method.

[Shroomer]

yeah... Icynene makes a special product just for this purpose. It still needs to be professionally installed, though.