Historic HomeWorks Forum

woodturner · Posted: Mon Oct 09, 2006 7:05 am Post subject: roof collapse? how to fix?

I am reroofing the shed roof of the covered porch attached to my 1930's colonial in Western Pennsylvania.

The original roof was slate, and the roof sheathing is individual boards, 6" wide or so. The sheathing seems to be in reasonable condition.

The problem is where the roof meets the house. I can't see well enough to be certain, but I suspect that 2x4's were attached to the balloon framing of the house, extending through the brick veneer, and then a ledger was nailed to those 2x4's.

What I see is apparently a ledger against the house, then places where one brick was left out and those places are filled with wood. Much of the wood is dry rotted, particularly in one area, and the roof is "drooping" about an inch where that area meets the house.

I'd like to do something fairly quick and easy to stabilize the roof for now. I have maybe one more weekend to get this done - they are starting to call for snow.

I do not have good access below - there is a ceiling. The longer term plan would be to remove the ceiling, go from below, put a new ledger below, through bolted into the house framing, sister the rafters, and jack the drooping part back into place.

What do you think? Any thoughts, ideas, suggestions are most welcome.

Thanks.

johnleeke · Posted: Mon Oct 09, 2006 8:37 am Post subject:

It's hard to give detailed structural advice without knowing more. Can you post a couple of photos?

One plan to consider might be to temporarily support the roof structure where it meets the house by screwing a 2x10 flat "plate" to the ceiling where it meets the wall of the house, then screw in vertical 2x4 or 4x4 posts from the plate down to sound and stable footings at the floor level.

emrude · Joined: 21 Aug 2006 Posts: 17

Ralph,
It is a shame you can't fix it right now, but we all have so many things to do to our old houses.
If I read your post right the roof is sagging, is the ceiling attached to bottom of roof so it is sagging also? If this is the case, follow John's advice.
If your ceiling is dropped and hung from ceiling joists, then from the top I would open space by ledger. Maybe removing two sheathing boards. Then using a 2x8 or larger(placed on end and spanning across rafters) on top of roof I would pull up rafter using bessy clamp(s) until sag is gone. Then slide in new ledger (spanning as many rafters as you can) to sister on top of old one. I would attach these with deck screws. Once new ledger is in place lower rafter back in place. If sag is spanning more than one rafter use more clamps. I have pulled joist and decks together using clamps, but my weight was not on top. I don't know if this make sense to you and if I were looking at your roof I might not agree with what I've just written.
Good luck,
Marion

woodturner · Posted: Tue Oct 10, 2006 7:32 am Post subject: more info

Thanks for the replies. I'll try to take some pictures, but it's difficult because I can't really see most of the structure.

I'll try to explain a bit more what I am seeing. The roof is a shed roof - a single sloped plane, attached to the house. I assume a ledger was attached to the house by nailing to the 2x's that extend through the brick veneer of the house wall. In any event, the rafters are attached to a ledger board that is against the house.

The joists that support the ceiling are attached to the rafters were they meet at the other edge of the roof (ie by the gutter). I am not sure how they are attached to the wall - I'm guessing another ledger, but I will have to check and see.

The idea of pulling the sagging part up with clamps seems like a good idea. There should not be too much weight on the roof - it's just the sheathing and roofing felt currently.

If there is a practical way to fix this now, before I finish shingling, that would be best. I am a "weekend warrior" so I realistically on get 8 to 10 hours a week to work on outside of the house, weather cooperating of course. I really do need to get the roof watertight this weekend, but I could probably take 4-5 hours to fix or stabilize this.

Thanks for all the help!

woodturner · Posted: Tue Oct 10, 2006 7:35 am Post subject: oops - forgot ceiling part

Forgot to mention that the ceiling is NOT drooping - just the roof. I think the joists are separate from the rafters where they meet the house, and are tied into the house framing but not the rafters, but I'll have to check that.

woodturner · Posted: Sun Oct 15, 2006 7:32 am Post subject: now with PICTURES

OK, I pulled a sheathing board and took a picture.

The ledger was originally a 1x8, and is mostly gone. There were signs of insect damage (termites? carpenter ants? Have had lots of problems with carpenter ants, but the galleries were kind of small for them) but no signs of mud tunnels or damage to adjacent wood.

The "ledge pieces" are NOT tied into the house framing - they are just a "post" that fits into a missing brick space in the brick veneer. The ledger was nailed to that to support it.

My plan is to cut back the rafters, install a 2x8 ledger screwed to new "post" pieces, end nail the last rafter to the end of the ledger, and use hangars to attach the "loose" rafters to the new ledger. I will also sister a shorter piece over the joint between the new ledger and the old (intact) ledger at the other end of the roof.

When I renovate the room below (a project for this winter) I will remove the ceiling, so I can get to the ledger from below, and install sleeve anchors into the brick to provide more support. I will also install a second ledger, the full width of the roof, below the existing and new ledgers, adn sleeve anchor that into the brick. Thus the rafters will be supported by (resting on) this second ledger -both the rafters I repaired and the ones that seem OK.

How does that sound?

emrude · Joined: 21 Aug 2006 Posts: 17

Okay,
I would open ceiling from below now. Why? You need to support this roof while you fix it and if you are going to open in a month or so--just do it now and get on with it. I would support below the ceiling joists. You could run a fake header across the room and put post three or four places along header.
Then you could jack the roof rafters up until they are level at top( run a string from end to end as guide. Once rafter is up add brace to support it using ceiling joists as base.
Now get rid of ledger. I would try to take it all out. If you put in a 2x8 pressure treated that would take care of ants-- as long as roof is dry. Hangers would work to support rafters. Of course, you will have to trim the ends of all of the rafters to fit new ledger. If rafter is soft after cutting to trim for ledger, I would remove all soft wood and sister rafter. I would use tapcons to screw ledger into bricks--unless you have really soft brick then I would use anchors.
As far as your roof staying dry--that is not going to happen unless you put in flashing. I would grind out mortar and install copper flashing the length of roof.
I hope this gives you a few ideas.
Good luck,
Marion

woodturner · Posted: Mon Oct 16, 2006 7:15 am Post subject: Thanks for the advice

Thanks for the advice and comments.

I worked with it a bit yesterday afternoon. Cut back oen of the rafters, installed a new ledger to the wall, then found I couldn't move the rafter enough with clamps to get it into place. Also noticed how unstable and "flexy" it was.

I read your response this morning, and it makes a lot of sense. I think supporting from below is the thing to do - and will solve the problem of not getting the rafters lifted up enough (I can use a bottle jack from below).

I'm still concerned about getting the shingles on before it gets too cold or snows, but agree that I need to fix this first.

Thanks.

woodturner · Posted: Mon Oct 16, 2006 7:22 am Post subject: Is it safe to attach to the brick

One other question - I have been concerned about using anchors or tapcons into the brick or mortar, for fear of damaging the wall.

It is brick veneer - balloon framed with a single wythe of brick veneer. It was built in 1936 or so, and there are some mortar cracks and other issues with the brick. I have been concerned about putting too much load on the brick, for fear of pulling down the wall or causing it to separate from the framing.

What do you think? Another option would be to frame a 2x wall in front of the brick wall, resting on the concrete floor slab and extending through the ceiling to support the rafters.

BTW, there was flashing on that wall, and in good condition. Yesterday I figured out how the water got in - the window sill brick needed to be repointed, had been caulked, but was apparently leaking - so the water came in through the window sill brick and got to the wood below the flashing.

Thanks.

woodturner · Posted: Fri Oct 20, 2006 7:23 am Post subject: tying to brick wall and update

Thanks for the comments.

I've been concerned about any type of fastener that attaches by exerting pressure on the brick or mortar - tapcons, sleeve anchors, etc.

I do like the Simpson and Hilti epoxy fasteners, but around here there are somewhat difficult to obtain and are VERY expensive.

I previously needed to attach a ledger for an enclosed deck/shed to the building, on the far side of this part of the building. That part is brick veneer over concrete block, but I was concerned about the strength of the brick and mortar. What I did for that application was to drill through the brick into the edge of the poured concrete floor/ceiling, then installed threaded rod using Resiweld, attached to both the brick and the concrete floor.

That has been stable and has held well for a couple of years now. I've thought about doing that for this ledger, too, but am concerned about attaching to the brick because that part is brick veneer over wood frame. I really should through bolt to the studs, but am hesitant to start cutting a lot of holes in the plaster. I've also considered that the last floor joist should be more or less where the ledger is, so if I could find (or have made) a threaded rod with a screw end, I could just drill a hole and screw it into the joist.

The simplest thing, though, seems to be to frame a wall below, sitting on the concrete floor, up to the ceiling joists. Then build a shorter wall from the joists to the rafters.

As an interim, I have installed a new ledger using the "pockets" in the wall, and sistered and attached several rafters. It seems solid enough now that it is not in danger of collapsing, so now I can work back through to sister and reattach the rest of the rafters, then repeat the process for the other ledger.

Then I will will finish the roofing/shingling so the building is dry, then go back and frame and install the walls I mentioned.

Or at least that is the plan at the moment. John had suggested that I consult an engineer, and that is advice I am planning to take before continuing.