Health problems for rebuilding on burnt concrete slab

[visitor]

Has anyone gathered information on the health problems of rebuilding on the concrete slab of a burnt house? I have just bought a house and the previous owner failed to notify me that it had been rebuilt on a foundation that was burnt during a house fire.

 

[Ron]

Unless the slab has been contaminated with some hazardous material (unlikely in a residence), the health risks are low to nil, assuming the slab was properly cleaned.

Here are a few functional issues that can develop from fire on concrete slabs....

Drying from the fire likely caused shrinkage of the slab, thus creating new or opening old cracks.

The heat from the fire probably caused at least some carbonation of the surface of the concrete, which can cause bonding problems with tile or other barrier surfaces (carpet not problem).

Moisture from the extinguishing of the fire may still be latent in the concrete and can cause problems with bonding of barrier coverings such as tile or wood flooring.

Some odor may remain.

Also, failure to disclose this may be a violation of state law. Check with your local real estate board. Both the previous owner and the realtor (assuming one was involved)might be culpable for claims in some jurisdictions.

 

[dik]

I get involved in half a dozen or so fire investigations a year and in addition to the comments that Ron has made, heat rises and the impact on foundation slabs is generally minimal except for health issues; slabs, however, can generally be cleaned and odours encapsulated.

With a prolonged fire, sometimes radiation heat causes the slab spall when it is hit with fire suppression water.

A bigger problem in northern areas and during winter time comes from large amounts of water used in putting out the fire. We have experienced problems with heaving of the slab as well as the foundation wall. In one instance, the foundation wall was 'jacked' approx 4".