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Can a slab-on-grade be salvaged after a burn-out?

fat... you have no vapor issues in CO?

To skew the topic a little.. I just sat thru a meeting with Roux associates.. they do mostly environmental stuff... the biggest new thing in their field is contaminated vapors from contaminated soil ... just a thought.
 
Yeah.. been there... BUT this new thing is vapors from contaminated soil (which can travel a long way)... old UST for example.. all the liquid needs to do is find a sanitary or storm or water line to follow and it's there... I think we'll be reconsidering slab vapor barriers everywhere.. all vapors need it differential pressure to get into the building.

Hi Fat, btw...
 
Hey back peachy........Yes, we are in the middle of finding out about travelling vapors, have a odor problem popping up in some basements in a subdivision, that we can't figure out how its getting there. How far do you think vapor can travel underground? Very frustrating, not the city's problem per se, but in the interest of customer service we are trying to figure it out.
 
Hi Everyone,

I am new to site and greatly appreciate your advice on my question in advance !

There is a fire damage house in Virginia that I am starting to rebuild.

This is new to me, what is the safest approach to make sure the slab is ok to rebuild on?

Thanks for you help
 
Depending on how bad the fire was, it might not be acceptable. I would recommend you engage an engineer to examine the slab and issue a report.
 
Yes. Call and talk with them, most will tell you over the phone if they can do the job or will refer you to someone who can.
 
I have witnessed many concrete slabs reused after a fire. There is no easy way to determine if the slab has been damaged unless there is spalling or color changes. If the use was something that would stress the concrete it might be an issue but a house.......not so much. Tap it with a hammer. I used to find bad spots in pool plaster by dragging a hammer head across the plaster....It was easy to find bad spots just by the sound.
 
I used to find bad spots in pool plaster by dragging a hammer head across the plaster....It was easy to find bad spots just by the sound.
Dragging a chain across a concrete slab is a recognized method of finding hollow areas.
 
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Jobsaver,

IMO, most of the intense heat went up and not downward. Also, how thick do you believe the slab area to be?

Again, IMO, a typical 3.5 inch thick slab would not be affected enough to be detrimental to reframing upon it.

In this area, we have had houses burn down to the ground, that were originally constructed on a "slab on grade"

foundation. The DWV system was in tact except for some charring, slight damage at the surface.

The "new" house was rebuilt right on top of the existing slab. "New" anchoring bolts were installed and away

they went.

.

Depends on how "green" the slab is. Too green and they may blow up. I have seen it happen.
 
I've required the use of a Schmidt Hammer for nondestructive concrete strength tests in the past. Just make sure that the hammer has been calibrated recently.
 
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