An upcoming project I will be working on soon is a porch attached to an old home that has exterior walls constructed of two thicknesses of brick above the basement walls which are three thicknesses thick, then parged on each side. The 2×10 floor joists are set right on top of the basement wall, no header joist is visible from the basement. The joists just run into the inner course of brick which holds them upright and on center.
The porch floor will be 7″ below the finished floor in the house. The porch floor joists will be perpendicular to the house and hangered to a 2×12 ledger. I’m considering attaching the 2×12 PT ledger to the basement wall with 1/2″ HD Galv threaded rods in each joist bay, alternating high and low in every other bay, and 1/4″ plate as oversized washers on the inside to help spread the force to more than one or two brick. I’m considering the 2×12 ledger, rather than 2×10, so that I have 8″ below the top of the thicker basement wall to alternate the threaded rod .
The ceiling and hip roof attachment will be equally challenging since it will be attached to the wall that is only two bricks thick and I cannot penetrate to the inside to through bolt. How about threaded rod epoxyed 6″ into the brick on 24″ centers to help spread the withdrawal stress?
Anyone have any experience with this type of project?
Replies
IMHO you should penetrate through the walls for the roof & ceiling ledgers...
I've seen, on old buildingd, iron rods that penetrated through & than were bolted through an angle attached to floor joists...
Epoxy might be OK, sort of depends on how the 2 layer brick wall was laid up (how many bond coursed) and how sound the mortar is.
JRnJB,
Thanks for the response!
Penetrating thru the walls for the roof and ceiling is not an option the homeowner wants to persue b/c the nuts, washers and rod ends would be protuding into an already too narrow hall on the second floor.
That is why I came up with the epoxy option. I'm thinking that if I keep the rods closely spaced, and penetrate into the inner course, the withdrawal forces would be spread over more points.
Any other ideas out there?
The bolts are just to hold the deck and roof into the house,right. Were you going to put something against the house[4x4 for instance] under the deck to carry the weight? Same for the porch rack?
I didn't do it....the buck does NOT stop here.
I would have the HO pony up for an engineer's opinion on this one. I wouldn't trust epoxy to hold a roof and ceiling.
My gut tells me to build a completely free-standing structure that simply ties into the house. You still would need the engineer's stamp on the tie-in... but it would be much safer and probably much easier than trying to make a square peg fit into the round hole you are faced with.
I guess you are all confirming what I that little voice in the back of my mind has been saying. Best solution is to pour a second set of piers just off the house to support a beam that would carry the house side loads. Then build the porch free of the house and just use the threaded rods for snugging up to the exterior wall rather than to support the house side loads of the floor, ceiling, and roof.
I'm still open to other ideas if any are offered.
While I'm all for having things like this "engineered", it doesn't hurt to think about what you are trying to do...for example, the existing 2 course brick wall has been holding up the roof since the house was built....also, the second floor deck must be attached to the same brick wall.....
you generally won't go wrong by over-building something, but you might spend more.....sometimes much more....than needed.
you write
'The ceiling and hip roof attachment will be equally challenging since it will be attached '
Is the interior exposed brick?....if not, then you can indeed through bolt....you'll just have some plaster/drywall repair to do.
IMHO, since you will need footers for your new porch, you might as well add columns to take the bearing load of the roof and ceiling at the old house exterior wall;then epoxied bolts should suffice to tie in.....