Slab jacking with wall foam | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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blahood2 Posted: Aug 20, 2016 08:57 PM	Slab jacking with wall foam Hi, Can anyone here tell me if there is a way to use standard polyurethane wall foam to raise a concrete slab. We are going to use the Fusion AP with the slab raising attachment, but are wondering if there is a way to get the wall foam to function as slab raising foam. According to specifications, slab raising foam should expand quickly (10-30 seconds), but not reach full hardness until about 15 minutes. Can I simply change certain variables in my wall foam (i.e. the temperature, ratios) to get it to work for slabs? If not can anyone recommend a type of foam to use? Thanks
blahood2 Posted: Aug 20, 2016 09:01 PM	Out manufacturer does not make a polyurethane foam for slab raising, and is unsure how to do it.
blahood2 Posted: Aug 20, 2016 09:01 PM	Out manufacturer does not make a polyurethane foam for slab raising, and is unsure how to do it.
mason Posted: Aug 21, 2016 06:46 PM	Wall foam is not what is used in slab lifting. They use a much slower rise foam for that application to prevent the potential for excessive exothermic heat and to have the correct cell structure. For example, wall foam typically has a cream time (time it takes for the foam to begin to rise) of 2-5 seconds and a rise time of 5-10 seconds. If you install foam over rising foam, it will hurt the cell structure and cause greater heat within the foam. In extreme cases, it can catch on fire. Slab lifting foam is actually a pour in place product with a cream time of around 20-30 seconds and rise time of 1-2 minutes. In thicker slab lifting applications, the cream time can exceed a minute with a rise time of 4-6 minutes. So, look for a supplier that specializes in the field of slab lifting and has the training specific for that application. I know NCFI has the foam and training available. Others may also, contact their technical department for help. Also, get references of other companies that they have trained. I was hired a couple of years ago to investigate a slab lifting application that caught on fire. The contractor was out thousands of dollars and went broke because of it. So be careful, do your homework and get with the right supplier.
CJKEVIN Posted: Aug 24, 2016 12:32 PM	Contact NCFI or any number of other geo-tech foam manufacturers for information on the proper foam system to use, and optimal gun setup. Also, from 3 years of personal experience I can tell you that the Fusion AP is going to give you some serious trouble if you encounter any sort of backpressure (you will) even with some sort of slab raising attachment installed. A GX-7 is a much more appropriate and user-friendly gun to use for slab lifting. If you have any questions about material suppliers, foam systems, or the right equipment set-up give me a call. (757) 592-8414. Kevin

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Comments

blahood2

Posted: Aug 20, 2016 08:57 PM

Slab jacking with wall foam

Hi, Can anyone here tell me if there is a way to use standard polyurethane wall foam to raise a concrete slab. We are going to use the Fusion AP with the slab raising attachment, but are wondering if there is a way to get the wall foam to function as slab raising foam. According to specifications, slab raising foam should expand quickly (10-30 seconds), but not reach full hardness until about 15 minutes. Can I simply change certain variables in my wall foam (i.e. the temperature, ratios) to get it to work for slabs? If not can anyone recommend a type of foam to use?
Thanks

blahood2

Posted: Aug 20, 2016 09:01 PM

Out manufacturer does not make a polyurethane foam for slab raising, and is unsure how to do it.

blahood2

Posted: Aug 20, 2016 09:01 PM

Out manufacturer does not make a polyurethane foam for slab raising, and is unsure how to do it.

mason

Posted: Aug 21, 2016 06:46 PM

Wall foam is not what is used in slab lifting. They use a much slower rise foam for that application to prevent the potential for excessive exothermic heat and to have the correct cell structure. For example, wall foam typically has a cream time (time it takes for the foam to begin to rise) of 2-5 seconds and a rise time of 5-10 seconds. If you install foam over rising foam, it will hurt the cell structure and cause greater heat within the foam. In extreme cases, it can catch on fire. Slab lifting foam is actually a pour in place product with a cream time of around 20-30 seconds and rise time of 1-2 minutes. In thicker slab lifting applications, the cream time can exceed a minute with a rise time of 4-6 minutes.

So, look for a supplier that specializes in the field of slab lifting and has the training specific for that application. I know NCFI has the foam and training available. Others may also, contact their technical department for help. Also, get references of other companies that they have trained.

I was hired a couple of years ago to investigate a slab lifting application that caught on fire. The contractor was out thousands of dollars and went broke because of it. So be careful, do your homework and get with the right supplier.

CJKEVIN

Posted: Aug 24, 2016 12:32 PM

Contact NCFI or any number of other geo-tech foam manufacturers for information on the proper foam system to use, and optimal gun setup. Also, from 3 years of personal experience I can tell you that the Fusion AP is going to give you some serious trouble if you encounter any sort of backpressure (you will) even with some sort of slab raising attachment installed. A GX-7 is a much more appropriate and user-friendly gun to use for slab lifting. If you have any questions about material suppliers, foam systems, or the right equipment set-up give me a call. (757) 592-8414.
Kevin

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