I have to hang the “Mantle Tree” at the e-house. It is a 1foot square x 9′-6″ long hollow box made from Oak.
The wall are masonry block made from a material they referred to as AAC(I think) which to me seems like an air-entrained, whipped-up-like pudding type of material. They claim it can be sawn or routed with carbide cutters, and that you can drive screws right into it. I say BS. I gave it a shot today with some Tapcons, and it really sucked. One twist too many with a manually operated screwdriver strips it right out.
What’s the best way to do this? Lead shield&lag bolts? I’m thinking 1/4″ or 5/16″x3″(2-1/4″into the masonry), as it is supported by a 4″ ledge for 8″ of it’s length. The lags&shields would keep it from tipping. Is there something better than this?
Replies
It's pretty soft. I think I might try the Tapcons again, only with a smaller pilot drill. You might have to go to a numbered drill size or possibly a metric to get a good fit. The difference between two adjacent fractional drill sizes would probably be too much, even if you have the drill set with 1/64" steps.
Dave,
The most reliably strong solution, short of through-bolting (usually not an option with mantels!) is to use chemical anchors. This is another way of saying to glue all-thread into drilled holes with special epoxy or acrylic compounds, extruded from a proprietary caulking gun. Simpson and Hilti are two brands commonly available at HD. There are others. If the masonry will get hot there, check with your supplier of bonding goo.
Simpson makes an epoxy cartridge that fits a regular 10 ounce caulking gun. This would be the way to go if you will not be doing a lot of this. The special twin-barrelled guns cost a lot, and are only useful for this one application.
Another idea, less strong, is to use the Reisser lags into the foamed masonry stuff with a proper pilot hole. Their threads are wide and sharp and well-shaped. But the glued studs are the stronger method, no doubt.
Bill
Dave, I have to agree with Bill. The chemical bonding is the strongest I have found. Just be sure that after you have drilled your hole that you blow it out good with compressed air. The drill dust will make the bonding fail.
James Hart