sand deposits at hearth extension

[jim baird]

These sand deposits were found on an inspect of a house unoccupied for an unknown time period. Massive chimney column rises from ground all the way up and through.

Comments?34238

[Elizabeth Chambers]

These sand deposits were found on an inspect of a house unoccupied for an unknown time period. Massive chimney column rises from ground all the way up and through.

Comments?34238

Brick termites? Somebody throwing sandbags against the fireplace for fun? The answer to this sand deposit mistery is awaitng further investigation by you. oo

[Jeff Zehnder]

Improper mortar mix

[Jim Hintz]

Mason-ry Bees ! Probably weren't Union -

[Nick Ostrowski]

Looks like efflorescence on some of the bricks on the surround. My guess is moisture penetration through the chimney and powdering up of the brick from moisture. Any issues on the exterior chimney structure like damaged pointing or a damaged mortar cap?

[Joseph Ehrhardt]

I can?t tell from my phone photo but masons years ago and today fill the void behind the fire brick and masonry block with sand , allows for thermal expansion with out the rigidity of cement or brick causing resistance.

[Caren James]

Brick termites? Somebody throwing sandbags against the fireplace for fun? The answer to this sand deposit mistery is awaitng further investigation by you. oo

I also first thought of brick termites. But can't be sure. Did you find any specific thing @Jim?

[Jim Hintz]

I agree with Nick about the efflorescence. I've seen it when fireplaces are located in basements that aren't occupied / kept warm.

[Bob Harper]

Efflorescence but also mortar deterioration from moisture. Whether moisture adsorbed into the surface then absorbed on the exterior face and crown or damp rising, water will be driven inwards and down by gravity and vapor diffusion. Once the salt concentrates, its like a magnet for more water and thus propagates an insidious cycle. The cool surface of a basement fireplace makes for a nice condensing surface for humid basements. Most people close the damper thus cutting off ventilation. Of course, being in a negative pressure zone, humid outdoor air would be drawn down the flue into the basement so correct the house's pressure regimes.