Green Remodel Forum

My house is 35 years old and there is insulation in the walls. But I feel there is not enough of insulation in them because my house is still cold even with the heat on. Is it possible to add insulation to existing walls already have insulation?

It is difficult to add insulation if you already had insulation in the walls. I would suggest to air seal the holes and cracks and gaps as much as you can to prevent air leaks. Also air seal the attic and add more insulation help even more.

Adding insulation to the wall is difficult. I witnessed a friend experimenting to add blown in cellulose from the interior and exterior. But it was hard to get the cellulose or blown-in fiberglass into the wall because the obstruction of the existing fiberglass.. Then he try from the inside, cut a 6 inches by 16 inches drywall (so you can nail the drywall back on the studs later) about 54 inches above the floor across the exterior walls. He did the same for the upper wall, only cut the drywall higher. He then carefully removed the pieces of drywall and removing the fiberglass batts between the studs. Install blown-in cellulose. He nailed the drywall back on and cut a hole between each stud to prepare injecting cellulose into the wall. This procedure works well to dense pack the cellulose but very messy. It works well if you have an empty house to work with.

I'm pretty certain there are gaps and cracks from doors and windows. For the time being, I'll try to seal as much as I can and see how much improvement I get. Are there certain kinds of caulking I should use to seal those gaps?

You can try "Great Stuff" from Home Depot. Just spray on the gaps or holes. They are easy to use.

I tried the Great Stuff. It worked pretty well. I covered some big gaps between the laundry room and garage. And my laundry room is no longer drafty.

Check and feel around your house and seal as much as you can reach the areas, ie, all the joints, around the windows and doors, the pipes connecting to outside, such as washer and dryer, under the sinks in kitchen and bath, etc.

Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.

To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where it is. A qualified home energy auditor will include an insulation check as a routine part of a whole-house energy assessment. An energy assessment, also known as a home energy audit, will also help identify areas of your home that are in need of air sealing. (Before you insulate, you should make sure that your home is properly air sealed.)

If you don't want an energy assessment, you need to find out the following for yourself:

Where your home is, isn't, and/or should be insulated.
What type of insulation you have.
The R-value and the thickness or depth (inches) of the insulation you have.

Absolutely air seal first then insulate. Sealing the the cracks and gaps can prevent cold air coming in during winter time and warm air in the summer time. Fiberglass is commonly used and an inexpensive insulation material. But it's difficult to install properly for it to work well. If you use fiberglass make sure it's installed correctly. It should touch all six sides with no gaps, no void, and no compression. For any reason if you need to open the wall or any other areas with insulation, such as moisture got in the wall. Check to see if it's installed correctly. If not, fix it yourself to make it touch six sides. Or buy new fiberglass to install it properly yourself.

Yes Instead of adding insulation, sealing of gaps and holes will be more easy for you. while adding insulation is little difficult and you may be you will need some rennovations to do in your house.
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