I hired a roofer to do a complete roof replacement. There are quite a bit of rotted lumber from leaks as well as termite damages. They had to sister in some 2X8 on the flat roof because the rafter tails had to be reinforced to install the sub-fascia and fascia.

The top side of the flat roof is already completed and passed inspection. I have circled the area where the issue is on the underside. Unfortunately I do not have a picture of the framing on the top side prior to the plywood installation.







Now on the underside right there, the ceiling dropped. At first I thought may be the ceiling was already weak and loose from previous roof leaks, and since the contract does not cover any underside damages, I have to install new ceiling sheetrock. So I pulled the ceiling rock down.

What I noticed is the new sistered 2X8s is lower then the original 2X8s. In the picture below, you can see three pieces of new 2X8s (lighter color), and those were installed lower than the original 2X8s.





They lined up with the original 2X8 at the top of the exterior walls, but dropped down below them on the other end. How much lower? About 5/8".



I am thinking the ceiling collapsed because when they inserted the new 2X8, there were debris on top of the ceiling, they hammered the lumber down anyway, causing it to come loose. Once it got loose and dropped down 1/2" or so, they continue to hammer the lumber to match the loose ceiling.

If I feel the top of those new 2X8s, I can insert my fingers between the 2X and the bottom of the plywood, I can even feel the shafts of some nails.

How can this be corrected?

You cannot disconnect the 2X8s from below, it's already been connected to the original 2X8s with many nails, as well as from the top side to the roof deck. I cannot install new ceiling with it protruding below like that. The top side seems fine, I guess the new plywood is sitting on the original half rotted rafters.

I haven't approached the roofer as I just noticed it this weekend and the job was last week. Final payment hasn't been made yet.

Is the only practical solution now to find a way to shave the bottom of the 2X8s flush with the original rafters? and not worry about the sliver on the top side?

 

This could easily be fixed with a power planer or sawzall.

 

I have many such repairs and don't see anything out of the ordinary. Trying to scab on sisters with old rotten and crooked wood with nails in the way can be difficult. If there were a roofing nail sticking down it probably kept them from getting that end of the sister all the way up. As Xsleeper mentioned fixing it is a simple matter of cutting off the offending bit that's sticking down. I would use a reciprocating saw but anything from a hand saw to a chisel could nip off the part hanging down.

 

The wood were not scabbed on from below with the roof deck and nails in the way. The original plywood deck was removed there and the scab was added FROM ABOVE. You do not see the ceiling there because I pulled them off AFTER THE JOB due to the ceiling came down half way.

The only interference they could have rain into are screws from below, say something like a junction box or a drywall anchor holding up a hook for a plant, or debris from the rotted wood. Something above the ceiling that was in the way of the new pieces. But I have no such things in that area of the ceiling except rotted rafter which could have debris.

 

OK I know it can be corrected from below with a sawzall, or a planar, or even an angle grinder with an aggressive flap disc.

But my concern was the top side. It's unusual to have ALL THREE pieces of 2X8s sistered crooked and off by this much. When you sister in typically you tap the new piece down until flush with the top of the original piece, yet all three pieces were tapped lower by 1/2" to 5/8". Why?

The only reason I can think of is they have pushed the ceiling loose somehow probably debris in the way of the sistered piece as they hammer it down pushing the ceiling out of the way, now they tapped the new pieces flushed with the loose ceiling at the bottom, but then they could have clearly see the top being off, but they didn't, and my only explanation is the top side was so rotted it crumbled enough to make it hard to judge. But there was enough loose material on the original 2X8 to allow the plywood to sit "right".

So now, my worry is I have the original rotted piece kind of holding up the plywood. The new 2X8s are sitting low on one side. The nails they shot in from the top is only partly secured to the new wood, so if I walk on that corner, the plywood may flex a little to allow the nail head to back out of the plywood and rip the paper and mopped tar. As I said I could fit my fingers in between the bottom of the plywood deck and the top of the new 2X8s as well as touched the shafts of the nails in between. Do I need to make small shims to tap in between and pack some wood filler into the slivers or am I overthinking?

 

You're the only one that can really see what they did and determine if it needs more "fixing". I do know that on old houses things are often far from free. Things can be made perfect but perfection has a cost.

 

I am not looking for perfection. I just want to be able to put back a new sheet of ceiling rock flush with the rest, and I worry about walking on that corner of the flat roof thinking nail heads will back into the mopped tar paper if I walk on it.

I spent a full day this weekend cleaning up around the entire perimeter, picking up nails, wrappings, gatorade bottles, old shingle pieces, dozens and dozens of tin caps old and new in the grass. As expected they broke the exterior in use cover of the electrical receptacle, yanked the entire cover off with the hinges. My garden hose has holes, they used it a bunch of time, probably someone had nails on their shoes and pierced it. My front hedges, where they parked their truck to do the boiling of the hot tar, that entire side of hedges about 12 feet across, has now turned totally brown from the heat. I am not worried about any of those, as I expect those pretty much. I change garden hose every time I have someone come do work, doesn't matter if it's painting, stucco, pest control, whatever, if they use the garden hose, then either the nozzle would be broken or the hose connection would be broken, as they do rough handling, rinse something off yanks it hard and throws it against the wall.

But the framing is an issue and it's more than just normal "sloppiness" IMHO.