EcoRenovator  

Go Back   EcoRenovator > Improvements > Geothermal & Heat Pumps
Advanced Search
 


Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 04-25-17, 01:13 PM   #1
Drake
DIY Guy
 
Join Date: Jan 2011
Location: Mpls,MN
Posts: 315
Thanks: 2
Thanked 17 Times in 17 Posts
Default Glass fiber reinforcement in thin slab mix???

Any opinions or knowledge of glass fiber in a thin slab mix for fracture prevention in a radiant hydronic floor being a poor choice? Glass is a good heat conductor as windows prove. My thin slab will also have rewire in it to secure hydronic tube to. I like how fibers have performed in other concrete floors I have done. Slab does not need to be light weight material(subfloor designed to hold it). Joists on 9"cc to fit pole barn steel siding subfloor which has 9"cc formed ridges.

Drake is offline   Reply With Quote
Old 04-25-17, 03:26 PM   #2
Fornax
Helper EcoRenovator
 
Join Date: Oct 2012
Location: Beuningen (Gld), the Netherlands
Posts: 64
Thanks: 4
Thanked 19 Times in 16 Posts
Default

Hi Drake,

I have no personal knowledge about using fibers as reinforcement but you say yourself you have good experiences with it.

Quote:
Originally Posted by Drake View Post
Glass is a good heat conductor as windows prove.
This statement though is not valid.
Glass by itself is not a supergood insulator but when compared to some metals it is a lousy conductor. Copper conducts heat about 400 times as good as glass, aluminium 250 times, carbonsteel 50 times and stainless steel 25 times. Most types of concrete conduct heat about 2 - 3 times better than glass.

The glassfibers being thin and only a small percentage of the floor the thermal characteristics won't hurt the performance of the floor much, I would not recommend against using fiberglass because of it not being a great heatconductor.
Fornax is offline   Reply With Quote
Old 04-25-17, 07:12 PM   #3
oil pan 4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
Default

What I would use is fiber reinforced mortar with polymer hardener and don't walk on it for at least a week, 2 would be better.
oil pan 4 is offline   Reply With Quote
Old 04-29-17, 10:26 PM   #4
philb
Apprentice EcoRenovator
 
Join Date: Nov 2010
Location: Oklahoma City
Posts: 155
Thanks: 58
Thanked 17 Times in 14 Posts
Default

I use polymer and polypropylene fiber in my mixes with very good results. I would think glass fiber will work if it is thoughlying encapsulated by the mix. Are you using a commercial mix or mixing your own?
philb is offline   Reply With Quote
Old 04-30-17, 09:36 AM   #5
Drake
DIY Guy
 
Join Date: Jan 2011
Location: Mpls,MN
Posts: 315
Thanks: 2
Thanked 17 Times in 17 Posts
Default

I have not yet chosen a thin slab mix. It will be 3/8' rod reinforced, 1" thick. It does not need to be self leveling or light weight. I am leaning toward a small arg premixed HS concrete as it is available bagged and I can use my mixer. What ratio of fiber do you add?
Drake is offline   Reply With Quote
Old 04-30-17, 09:40 AM   #6
oil pan 4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 1,026
Thanks: 12
Thanked 127 Times in 107 Posts
Default

Concrete is well known for its exceptionally bad insulating properties. You would have to do a lot to it to make it a decent insulator. Things such as use additives that increase foaming during mixing or add Styrofoam beads to it. A lot of Styrofoam beads.
oil pan 4 is offline   Reply With Quote
Old 04-30-17, 09:49 AM   #7
Drake
DIY Guy
 
Join Date: Jan 2011
Location: Mpls,MN
Posts: 315
Thanks: 2
Thanked 17 Times in 17 Posts
Default

This is for a passive solar heat sink and hydronic heated floor. Highly conductive material is desired not insulation. Insulation will be below floor to direct heat loss into living space.
Drake is offline   Reply With Quote
Old 04-30-17, 11:02 AM   #8
philb
Apprentice EcoRenovator
 
Join Date: Nov 2010
Location: Oklahoma City
Posts: 155
Thanks: 58
Thanked 17 Times in 14 Posts
Default

For a floor 1 inch thick, I would reconsider using 3/8 rebar. As a rule of thumb, rebar will need concrete 3/8 thick surrounding it, which is more than 1 inch. You could use 6x6 remesh in flat sheets. Remesh will still require some bending to get it flat. Alternatively, you could use metal stucco lath.

I used a mortar mixer to make the 3/4" ferrocement roof on my house. It has no reinforcement other than fiber.

For 6 cubic feet of mix I use 30 lbs portland, 150 lbs sand, 2 lbs dry polymer, 1 ounce of polypropylene fiber, water reducer/plastitizer, and 1.25 gallons of water. The polymer is actually ethylene vinyl acetate (VAE). VAE is found in everything from paints to coatings on solar panels and phones. It's also the main ingredient in Elmers wood glue and Tite Bond 2 glue. 1/2 cup of glue per 6 cubic ft of mix. Avoid paints with poly vinyl alcohol as it won't bond well. 1/2 gallon Latex paint base will work provided it is the last layer. Otherwise, it will cause delamination. I use electronic scales from Walmart to weigh each component.
At this point, I have used this mix for floors, walls and roofs. Water content is the key. You want the mix to be like peanut butter.
philb is offline   Reply With Quote
Old 04-30-17, 12:21 PM   #9
stevehull
Steve Hull
 
Join Date: Dec 2012
Location: hilly, tree covered Arcadia, OK USA
Posts: 826
Thanks: 241
Thanked 165 Times in 123 Posts
Default

Drake,

Is the surface of your thin slab going to be the final floor? If so, do not use fibers as they stick up and are very difficult to get a "clean" finish on the concrete surface.

An alternative is to put the fibers in the concrete, roughly level it out and within 12 hours pour on a 1/4 inch (4 mm) concrete floor leveler. The initially almost liquid floor leveler pours virtually flat and bonds exceptionally well to concrete if done with a few hours of the initial concrete pour.

But practice is key with floor leveler as it sets up VERY quickly. It can go from very liquid to a putty like substance in just 10 minutes. I love it as you can put on a perfectly smooth finish without all the finishing that a concrete floor surface requires. In fact, a "rough" surface is great as the floor leveler really grips into that rough concrete surface.

And the floor leveler can have a smooth almost glass like surface with no work. In fact, if you work floor leveler, it sets and then you don't have that smooth surface.

As you can tell, I love floor leveler and have used it in a garage, in a basement and on an outside patio. The cost savings was high as you don't have to pay for the expensive labor to smooth out the surface.

Steve
__________________
consulting on geothermal heating/cooling & rational energy use since 1990
stevehull is offline   Reply With Quote
Old 04-30-17, 01:21 PM   #10
Drake
DIY Guy
 
Join Date: Jan 2011
Location: Mpls,MN
Posts: 315
Thanks: 2
Thanked 17 Times in 17 Posts
Default

The slab will be covered with dark(for solar)porcelain tile which I can install myself so rough surface will be good for adhesion. I have used fiber in other slab projects just not with radiant floor.

Drake is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 03:58 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design