Connection of Timber Floor to Old Rubble masonry wall.
Connection of Timber Floor to Old Rubble masonry wall.
(OP)
Hi,
I was wondering if anyone had an opinion on a good detail of how to connect a new timber floor to an old rubble masonry wall. Basically the 1st and second floors are being removed and replaced in an old house. The external walls are 600mm thick. I was going to create a series of concrete pockets along the old wall and fill with 35N concrete (300x300mm). Then bolt a treated 5x2 timber with fixings at the pocket locations to the wall. I was then going to fix joist hangers from the 5x2 to support the floor joists. Anyone got a better idea?
Or should I think about bolting a channel section to the wall and sit the floor joists on the bottom flange of the channel section.
I guess I will need to provide pockets on the parallel walls also so I can tie strapping across the joists to these walls?
J.
I was wondering if anyone had an opinion on a good detail of how to connect a new timber floor to an old rubble masonry wall. Basically the 1st and second floors are being removed and replaced in an old house. The external walls are 600mm thick. I was going to create a series of concrete pockets along the old wall and fill with 35N concrete (300x300mm). Then bolt a treated 5x2 timber with fixings at the pocket locations to the wall. I was then going to fix joist hangers from the 5x2 to support the floor joists. Anyone got a better idea?
Or should I think about bolting a channel section to the wall and sit the floor joists on the bottom flange of the channel section.
I guess I will need to provide pockets on the parallel walls also so I can tie strapping across the joists to these walls?
J.






RE: Connection of Timber Floor to Old Rubble masonry wall.
RE: Connection of Timber Floor to Old Rubble masonry wall.
RE: Connection of Timber Floor to Old Rubble masonry wall.
I would say the OP has a good handle on a reasonable way to do it. I have, on occasion, seen epoxy anchors used directly into the stones, but that required numerous anchors to keep the load in each one quite low.
RE: Connection of Timber Floor to Old Rubble masonry wall.
The difficulty of your problem is that you and the contractor have to really evaluate the existing ruble stone wall in minute detail. If not, every individual connector will not be worth its cost, let alone the installation effort. You have to be fairly conservative in assigning strength to each connector, as a function of how every time you touch one brick or stone, you loosen the next three adjacent bricks or stones. In a grosse way, the wall is certainly capable of carrying the distributed loading of a new floor, or whatever, but if the brick or stone below the next new connector ends up loose because of your drilling action, or whatever, that connector is essentially worthless. Look back at the old details where each joist was fire cut and set into a pocket in the wall. If old joist/beam pockets could be used without disturbing the masonry, so much the better. While this may be some added work to accomplish, it is redundant, and most of the work can be hidden within the floor structure depth. Can you repoint and strengthen the wall at the immediate elevation of the new work. Those walls have supported that structure for hundreds of years and yet, the minute you start to disturb them, they just start to crumble, and there is no end, they just keep crumbling three stones in front of your work. With today’s diamond saws you can cut and chip fairly nice pockets in a masonry wall, assuming that the wall stays together during this process.
RE: Connection of Timber Floor to Old Rubble masonry wall.
It's good for their business to provide this service to engineers. Gives them face time with engineers and they hope we remember that on the big jobs. And, if they have a good product, I will.
RE: Connection of Timber Floor to Old Rubble masonry wall.
J.
RE: Connection of Timber Floor to Old Rubble masonry wall.