Filling basement cinder block for insulation.

diy4life

I have a question about basement walls again. Is it a good idea to fill your hollow basement cinder block with foams like Icynene? If not what would you fill the cinder blocks with to stop the air infiltration?

itsreallyconc

any insulation's always a good idea no matter where you're building but be sure you're getting the most bang for your busks,,, personally, i'd be placing foam on the outside even above grade,,, however, WHAT air infiltration as there shouldn't be ANY ! ! ! just the fact you're asking tells me there's trouble ahead.

its more important to be VERY sure you've got a GOOD wtr management system in place as, eventually, you'll have wtr infiltration problems,,, the code rqd system's DAMPPROOFING, NOT WATERPROOFING,,, a properly design'd/blt system may incl sumps & pumps if you can't ' run to daylite ',,, trust me - retrofit systems're MUCH more expensive - we're doing 4 right now.

1st things 1st ! ! !

bob22

I would insulate the inside of the wall; placing insulation into the cores would not do much since the rest of the block will easily allow heat transfer.

Maintenance 6

What Bob said. The U factor for masonry is so high that insulation inside of cores is almost useless. The only place that may help is to pack the open cores at the top of the wall to prevent convected air from traveling to or from the wall.

diy4life

Well, when you want real toasty warmth in your house and all you are getting is air that is heated only slightly or 50% even after doing all that you can do to make your house feel better, you become desperate and starts to look for more answers and solutions and only thing that comes to my mind is insulation and more insulation or replace my 80% furnace with new 90% or higher efficiency furnace. One of these options should fix our problem.

I know why my house feels cooler no matter how high we set our thermostat at, even though my furnace is acting like the way it supposed to, but for me to fix these problem would be a monumental tasks. Plus, I don't have the right tools or the expertise to fix them. Not only that, I am not rich either to have a contractor to do them for me.

Let me tell you what my dilemma is with my house. First of all, my house was built in 1921. It is a two story house, the living space is only 20ft x 30ft, has two bedroom on the top floor, living room in the first and basement in the bottom. So, imagine almost perfect cubes stacked up on top of each other. Because we spend most of our time in the living room, our time is spent sitting directly on top of our basement. Our basement has so many problems, which I have been fixing as much as possible. One of the major problems with my basement is air infiltration especially through its hollow cinder blocks walls on all four sides. Because our exterior walls sits right on top of our basement cinder blocks all the way around and having little interior walls but 85% exterior walls. As a result of our hollow cinder blocks' air infiltration hitting the bottom of our rim joists, our walls feels cold. There is ton of outside air running through the basement walls. Even though I've done my best to plug them up, it is still a problem.

As a result of all this, my house is unevenly heated. Half away up from my floor it feels cooler and half away upto the ceiling, its okay. After all this, I have my thermostat at 75F. When its around 50'ish or above outside, my 80% furnace doesn't put out much heat at all or hardly any. The colder it is outside the better the heat coming out of my furnace. After all my effort in resolving this issue, I really have two options at this time, either spend all of my savings on a new high efficiency furnace or spend it on insulating all of my basement walls with insulation by hiring a contractor.

I have 80% Arcoaire brand furnace.

What do you think I should do? Thanks in advance.

Scuba_Dave

Wait a minute, I thought you had sealed your house so well that air was not getting in & you had to leave a basement window open to let fresh air in ?

diy4life

I did as best I could and it has made it better, but the air tempature is still being conducted or transmitted through my floor and walls. .....

Scuba...thanks....for your comment....You just made my day LOL

Gary in WA

http://www.buildingscience.com/docum...ts?full_view=1

Hope this helps....
Be safe, Gary

__________________

Maintenance 6

Insulate the ring joist and under the floors and let the basement walls do whatever they want. You don't live down there. If you insist on sealing the basement, start by looking for the air leaks around the foundation and mortar them shut. Air can't get in below grade, so the cracks should be visible.