? about insulation

[Gregor 4,846]

I have mentioned before that I have a basement under my garage. The walls are poured concrete, the floor is also concrete. The garage itself also has a concrete floor, and it gets very cold. Would it do any good to glue Styrofoam insulation to the ceiling of the basement, to help keep the garage floor warmer? The garage is heated. If so, what type of glue works best for adhering Styrofoam, the extruded pink stuff, to concrete?

Thanks   Greg

[Pullstart 62,838]

It will have the same R value, no matter what.  I would recommend it, just make sure the gaps are glued as well.  I have a drywall lift, I imagine a tool like that would be a HUGE help in installation.  The insulation manufacturer might recommend a certain adhesive, but likely a liquid nails or construction adhesive would be just fine so long as the cement is clean and free of loose debris.

[Pullstart 62,838]

Keep in mind, there is R value in the cement as well.  It might be quite low, but for the insulation to be effective, it needs to be greater than the slab itself.  If you really wanted to get creative, adding some heat between the cement and the insulation would make the slab get toasty… it just takes a while to get there and it needs to stay there to be effective and efficient.  No temp changes from night to day, etc.  set it and forget it

[8ntruck 6,998]

Whatever adhesive you use, make sure it is comparable with the foam slabs.

[stevasaurus 22,721]

You have not given enough information to make an informed discussion...

1.  Is the basement heated also??

2.  Do you have a moisture issue??

   If you have a moisture issue, then I would recommend a moisture barrier 1st.  Plastic would do that, then you could use concrete screws with washers to install sheets of pink Styrofoam.  If you do not want to do that...Liquid Nails and a calk gun would glue the sheets to the ceiling.  I doubt that any of this would make a difference...heat rises.  You need to explain more of what you have going on.  Guess what...floors are cold.    Ceilings are warm...really need to know what you have there.

[Gregor 4,846]

The basement is not heated. No moisture problem to speak of. The floor in the garage is 4" of concrete, poured on top of pre-cast concrete slabs. The pre-cast is the ceiling in the basement

[gwest_ca-(File Mod) 11,041]

Why not insulate the basement walls? That would raise the temp and heat the floor.

You can not drive heat down into a floor.

About 20 years ago I glued SM to the concrete walls with the recommended adhesive. Just learned the SM has shrunk and pulled it's self off. Center of each panel still stuck. The 2' x 8' sheets are now 1/2" short. So much for installing it tight.

 

[Racinbob 11,058]

Make sure the adhesive you use specifically states that it works on polystyrene or whatever type of foam board you have. The majority of the adhesives out there will eat the foam. A couple years ago I fastened about 100 sheets of drywall to our exposed polystyrene Ice Block basement walls. I used Loctite Power Grab and it worked great. 

[CCW 1,295]

I think you are going to find that once the concrete is cold, it stays cold.  You may have better luck putting something on top of the floor to stand on.

[Jeff-C175 7,200]

19 hours ago, stevasaurus said:

..heat rises.

 

Heated AIR rises.

 

Heat energy (rays) travel in all directions from warmer to cooler.  

 

17 hours ago, gwest_ca said:

You can not drive heat down into a floor.

 

Why not?  If the air around the floor is warmer, heat energy will transfer into the floor by radiation.

 

Point one of those infra-red heat lamps at the floor and it will get warmer.

 

The problem is that the floor is probably losing heat faster than it can absorb it.  Insulating the exposed outer perimeter of the foundation and slab would probably give more bang for the buck.  Prevent the heat from conducting into the surrounding soil.

 

That slab will always feel cold though, no matter what you do.

[Handy Don 12,214]

 

25 minutes ago, Jeff-C175 said:

The problem is that the floor is probably losing heat faster than it can absorb it.  Insulating the exposed outer perimeter of the foundation and slab would probably give more bang for the buck.  Prevent the heat from conducting into the surrounding soil.

 

That slab will always feel cold though, no matter what you do.

Concrete is a surprisingly good conductor of heat. To be a practical thermal mass, it has to be completely insulated from heat sinks.

Even if you chose to heat the slab from below (circulating hot water, for example) and insulated below it, a LOT of heat will escape out the sides.

 

55 minutes ago, CCW said:

I think you are going to find that once the concrete is cold, it stays cold.  You may have better luck putting something on top of the floor to stand on.

Budget and practicality will rule, of course, but laying a vapor-barrier and insulated floor atop the concrete can work.

Going a step further, you could add radiant heat in the overlaid floor (only in open areas--not under storage or furniture).

Edited October 18, 2022 by Handy Don

[Jeff-C175 7,200]

24 minutes ago, Handy Don said:

Concrete is a surprisingly good conductor of heat

 

It is.  That's actually why it 'feels' cold all the time.  In itself it is a heat sink.  When you touch it, it sinks the heat from your body thus 'feeling' cold.  (If it's colder than your skin, or shoes).

 

"Driving Force" is a b1tc4.