Adding Wall Insulation

Nice writing. You are on my RSS reader now so I can read more from you down the road.

Allen Taylor

I am remodeling and adding on to a home that was my grandfathers first home. It was build in the early 1900s. I’m not too worried about the cold as I am the Heat here in texas. What can I do to it to make it more energy effecient in the summer? It has no insulation, shiplap walls, hardwood floors, and ceiling, and tin roof… I have been kicking around the idea of insulating the attic and floor, and possibly getting insulation blown into the walls as well.. Thank you Wesley Peschel

Is it possible to add cellulose insulation in older homes - possibly via holes in topplates in attic? Any thoughts?

Isn’t it costly to add this insulation? Would replacing windows be a better alternative?

Actually replacing your windows is NOT a cost effective thing to do. Studies have shown putting storm windows on them you will get your money back under 5 years. Replacing your windows you won’t get your money back for over 200 years!! Go figure. Also I believe there have been studies that say putting the newer storm windows over old windows insulates better than the new double pain windows.

I would not agree that wall insulation is not worthwhile. It was relatively easy to dense pack the walls in our 1920s bungalow with cellulose and not very expensive. The house is so much more comfortable and when combined with air sealing and attic insulation, we cut our gas bills in half! We had the walls inspected pre and post insulation with an infrared camera so that no spots were missed. We did not replace the windows - that was less cost-effective.

I just bought a house built in 1912. Love the old house but have no Idea where to start. It is very cold. First thing this year I will put in a newer furnace and a batt of insulation in the attic. Then maybe the basement floors. The walls stay cold. It is a two story with a full attic and basement. Any idea’s please let me know..It is a brown stone with plaster walls.

I called in Insulation contractor to see if I need extra insulation in exterior walls because I feel it is too cold in winter time and hot in summer, the walls are brick and inside is plaster, after putting a 1 inch hole from inside he discovered there is an paperback insulation and he discouraged me to have use cellulose blowed in. On the other hand he was insisting to put insulation on the attic, anyway I did not do either so far, Now if you do not mind I want to ask; 1st. for the attic, there is a paper (vapour barrier) under the batt insulation cut to fit between ceiling joists then they put insulation on the paper, do I should change this paper or leave it?. What shpould I use to replace it?. 2nd. Should I add insulation in exterior walls and what type? Thank you in advance and I hope get a response from you…

I read the previous comments and your recommendations in how to insulate old houses and they make at lot sense. I own a 100+ year house with the first floor having red-stone walls and he second floor a letter addition having aluminum siding. We have replaced the furnace as well as all the windows but now we are feeling the all the walls to be very cold and we have tried to covered all the places where we feel a draft; but unfortunately the house still feels very cold. Question 1. Any suggestions in how to best determined what we can do to insulate the walls and find any other drafts ourselves, without getting any professional help, if it is possible?

Wouldl ike to thank you in advanced for your help!

We have a 1915 home and are planning to insulate wrap and side over top of the existing wood siding . Is it necessary to wrap? Our plans are to leave out the wraping to save cost but our contracter claims that wraping is a must. We are also thinking of using steel siding. Is that recommened? If not why not?

Good information. In Florida where we have hot, humid attics and condensation is a big problem, spraying foam insulation on the underside of the roof deck and sealing off any soffit/ridge vents to create a “dry attic” has become very popular. With a temperature drop of easily 30 degrees, the house is more comfortable, energy costs drop, and in some cases the HVAC system can be reduced in size.

Great Article! Adding wall insulation could definitely be worth your while and can end up saving you tons down the road.

And Ida, your contractor is right - wrapping your home is essential when siding over the additional wood siding

Replacement Siding Houston

for wall insulation, i always use polyethylene foams and also polypropylene foams–`

The solution you are looking for is injection foam. It has many advantages over “blown-in” products. 1)It is done from the exterior of the home after a row of siding has been removed. 2) The drainage plane (house wrap) can be restored after injection. 3) It fills the wall cavity, no voids or missed areas. 4) Doesn’t settle over time 5) Has a much greater R-Value than blown-in products. Check out Tripolymer Injection Foam for more information.

Thank you for a frank look at adding insulation! I have a victorian built in 1902 and have vascillated over whether to insulate the walls, but have been concerned about the effects of uneven distribution and the like. Your article easily shifts my focus to updating the furnace (approx 50 yrs old - but still chugging!)
Thank you!

It’s worth the investment to have spray foam put into the walls of an older building. It’s kind of like how you can’t insulate just the attic of one office that’s in a long one-story building. You have to catch the walls as well, otherwise heat will simply transfer from the rooms on either side of you.

I think this is questionable advice. There are online tools available to help quantify energy upgrades (http://hes.lbl.gov/consumer/) is one from the US Department of Energy. I use another provided by my local utility. For a 2700 ft2 uninsulated Victorian, injecting foam into the walls would cost about $6000 and pay itself back in 6 or so years. If I heated with oil (which is much more expensive than gas) the payback was closer to 3 years. We did this from the outside, cutting shingles, driling holes, patching the holes and then replacing the shingles. No change is visible from outside the house.

Generally I’d insulate the attic first, work on sealing cracks and leaks and then look at the walls.

It is helpful to have wall insulations at home because it will help us a lot. Thus, it won’t cost as that much or i mean yeah it will cost us a little but it will really help us save our home in the future.

I purchased a newer home with an unfinished basement. It has concrete on 3 walls. The back wall is a 2X4 wall with R-13 faced insulation. I am adding furring strips to the walls, including concrete walls. I want to know two things, can I add insulation to the already insulated 2X4 walls since it already has faced insulation or will there be a vapor/water problem. Second what would be the best way to insulate the concrete portions. I am only using 1X3 for the furring strips. Also should I apply a vapor barrier on any parts of the basement.

Great post,all rooms except one in our Victorian solid walled semi have been gradually insulated internally over a long period, some nearly 24 years ago.

The insulation boards used were either 50mm polyurethane foam / plasterboard laminates (with an aluminum foil layer behind the plasterboard as a vapour barrier), installed by myself, or 30mm phenolic foam / plasterboard laminates (without an aluminum foil vapour barrier), installed by a contractor. However, both foams are closed cell and, AFAIK, impermeable to moisture vapour anyway. As belt and braces I have painted it all with 2 coats of Gyproc Dry Wall Sealer which is claimed to act as a vapour barrier in itself. Clearly vapour can still enter the wall round the edges of the boards and through any perforations.

Brian
Sound Insulation

We are renovating a family farm house that was built in 1912, as with the above family.. No insulation at all. we are more than willing to remove the inside of the exterior walls to put in the insulation and then put the walls back in place.(the entire house is made of planks) The attic is enormous, so not so worried about insulating it.. plenty of room to move around in. This house has never had heat/air, so we will be adding a unit in the attic, that will be the easiest to run the duct to each interior wall. Our worry is the floor. The house is on pier and beam, how do you insulate the floor?? Just underpinning? Is that going to be enough??

You say wall insulation is not recommended but you or TOH advises it in several places at your site.

Polyurethane foam roofing saves our roofs and walls from a great damage. I like the post. Thanks so much for posting.