This way the forces in the two internal walls are almost canceled, it would of been better if all the rooms were the same width.
Remember the cracks? Well after considerable talking (and feedback from some of you) we will this time put the arch over the wall with 1 cm of clay/sand mortar. After we are done with all the arches we will dig this mortar out. The reason being is the arches laying on the wall are not "settling" the same as the arches freestanding. We believe that is something that is causing some of the cracking. Later we will fill that gap with something flexible.
Matt, Jeff, Sean and others : what do you think?
Just so I'm clear, you are thinking that the vault should be free of your arched walls because they each expand and contract differently which may have caused the cracking. Correct? I would personally not start out using mortar then dig it out because I think it would cause separation cracks in the vault...kind of like when you remove wedges from under an such form. I would try to use an uncoupling layer, something that would not bond the vault brick to the wall brick but allows contact. What you can use is dependent on what you have available. But I'm thinking it should be something that allows a little movement but still maintains structural integrity of the vault. Of course, if I misunderstood then....nevermind!!
ReplyDeleteYou have understood i want vault to be free from the wall, at least for awhile. I am more concered about settling, that the wall will not settle the same as a vault.
ReplyDeleteI suppose seperation between the individual vaults COULD happen. I figure most settling happens quite quickly, so eventually i would put something maybe mortar back in there.
But also I am putting some steel, what i call weld mesh, along the top of the vault and then the plaster over that. that will stop any seperation in the vaults.
How about building your wall higher than the vault and once you start your vault let it lean into the wall but not on top of the wall? Is the wall acting as a fulcrum to the vault causing the cracking? How would this have been done 1000 years ago? I will look forward to see how you solve this problem.
ReplyDeleteChes,
Deleteyes a bit like a fulcrum. the cracking is only in the plaster though on the outside. there could be a crack between the arches on the wall and not on the wall, but you cant tell as it is a joint.
Hassan Fathy would of done like you said. but then i would have similar issue with separation between the wall and the vault. They would also move differently and you would get a hairline crack without steel reinforced tying together.
How would Hasan Fathy, who built many vaults, have done this?
ReplyDeleteErik,
ReplyDeleteDid you come to a final conclusion about whether the cracks were related to the forces from your eve extension, or whether this is truly occuring from the differential settling between wall and vault? Are the other brick vault buildings recently built experiecing cracking at the same locations? The vaults should be free standing. I like your idea about digging out the old plaster and closing things up again after settling. If that is the plan,(if that is the problem) then would you just butter one edge at the top of the wall for the refernce line and leave the inside open?
Jeff
Jeff, today I passed by those houses, and on many walls they have seperated in places from the vault, i mean there is a small crack on top of the wall. Then on same wall other places there is no crack.
ReplyDeletethe wall settles more than the vaults!
They almost all are settling.
Oops, I thought we were still talking about the crack in the vault at the edge of the eve (your October post). So the walls are shrinking vertically and the vault should be shrinking/expanding inward or outward. Bottom line: I have no idea how you would make a low-impact expansion joint with natural materials to accomodate movement, but have enough adhesion to connect the wall to the vault. I like digging out the temporary top mortar idea the best.
Deletehttp://www.angelfire.com/biz/BuildingPathology/crack.html
Jeff
Erik, this sounds like an issue with your footing if the wall is settling
ReplyDelete