How do i repair my portugese limestone fireplace?

i used 2 part filler

leon
January 2011

I actually paint on Portugese limestone tablestops for a company, but there are inherent problems in this stone. We have now changed to granite because of them.

Your problems are twofold, at least. Firstly, limestone is sedimentary rock, is soft and fractures easily, and that is why you have cracking. This is especially a problem around heat and rapid cooling - caused by your fireplace. We have had the same problem with tables that are used in patios where weather conditions change. Secondly, there seems to be a problem in how it was attached to your wall. I would recommend grouting it to the wall, but I don't know how much space has grown between the actual mantle/fireplace and the wall itself. It might be feasible to bolt and then grout to the wall. However, bolting can cause weak spots in the limestone, so the depth and width of the area of the stone to be bolted is important. I suggest getting advice from a stone mason who knows the inherent problems with limestone.

Deirdre Le Blanc
June 2008