Fixing Saggy Roof?

It’s the one over our favorite room, too, a big family room (20’ x 20’?) that was added-on by a previous owner. Only they chose to leave the ceiling open. The only place where a beam connects the two sides of the roof is way up high, maybe 2’ below the apex.

So it’s no wonder the roof looks concave from the exterior. Particularly the north side, where snow doesn’t melt away as fast.

Do I have someone build trusses and beams on the inside of the room, to give the roof proper support? That’s just a thousand bucks’ worth of 2x4’s, maybe?

Or is it cheaper to replace the saggy 4x8’s with a fresh set, with the logic that they’ll last 10 years anyway and retain the room’s high ceiling and open feel?

Or will I need to do both?

My Dad’s wondering if the room’s walls are bowing outward. I don’t see any cracks to indicate wall movement, just roof where it meets the existing house.

Thanks in advance for any/all opinions!

Call a contractor, because it’s not something anybody can help you with, unless they inspect the construction.

Oh I’m working on that, too. Left one msg Friday and will call two more today.

I just find a lot of value in hearing other people’s experiences.

There are too many things that can be happening and too many solutions to fix the problems all requiring fixes that comply with your building codes. Dad worked on this sort of thing most of his life and my brothers do now. I’m not just telling you to get a contractor, because I can’t think of a problem and solution.

Invite multiple contractors to look at the house.

You description is a bit confusing. Is it that the roof has rafters supporting it, but the only beams connecting the rafters on the two sides is about two feet from the apex? If so, what size are the rafters? Is there a ridge beam?

If you’re in an area where it snows, the roof should (by code) have rafters sized to support the probable snow load. If this was done correctly, and the rafters are spaced properly, then I’d be surprised to see much concavity in the roof after (10?) years, but any concavity would be harmless. If this was * not * done correctly, then it may actually be dangerous. So any contractor/engineer who comes in is going to do the size calculations on the rafters for the distance they’re spanning and will come up with some suggestions. Here’s a calculator you can use to make some guesses about your situation. To me, if they used 2x8’s for the rafters, then that sounds a bit undersized for your probable run.

Caveat here: I’m not in the building trades and have no idea what area or even country that you live in.

This sounds like construction that tool place without a building permit. You could check your local building department. That doesn’t offer you a solution though unless you had an inspection before buying and could claim the inspector failed to cite the code error, which is unlikely.

If you want it fixed you will need to replace the roof completely with a stable design. Don’t hesitate to get an inspection because you may have a safety issue. The roof may collapse.

M’kay, will make more calls right quick. Thanks!

Sorry for not using the correct terminology, I know that makes it harder to understand.

The roofing contractors walked all over it & said it’s fine. WoW such a relief!

My Dad was here visiting so he walked it with them, too. The twins were utterly fascinated “Grandpa’s on the roof!!!”.

Thanks for your help here. :slight_smile:

I’m glad to hear the news.

Glad it’s OK!

Did they say why it looks like it’s sagging? Is it sagging but fine, or is it an illusion somehow?

IANA engineer but It sounds like you have an A frame roof with horizontal connectors near the top. They are more or less in tension and add some stability to the roof in the event of high winds and give it some support from punching out. They do nothing for sag. This is how the attic of my house is set up except there are ceiling joists that act in tension to prevent the roof from kicking out. In your case, you don’t really have that and I wouldn’t be surprised if your walls were bowing out in the center.

If it’s sagging in the middle then I would suggest adding scissor cross members. Picture a beam in compression that goes from the base of one roof beam to the center of the opposing beam. You tie these 2 together where they cross. It would require that you span all the current beams where they sag so you can jack them up to the proper level. I would duplicate the horizontal beams you mentioned earlier and connect them in the center (where the new beams meet). It would be better to run 2 or 3 large beams at ceiling height to accomplish the same thing. Not only is your roof not well supported your walls don’t have lateral support. This is not the room to hide in during a storm.

Thanks for your suggestions! My Dad wondered about that, too, so we measured the wall-to-wall distance at 3 points and the difference amounted to an inch. My roofer thought that was fine. He thought the sag was just b/c the builder eyeballed it so it’s not perfectly even but not truly sagging. He said the addition was in better shape than the older roof, which has some soft spots (but the shingles are still in good shape so I should be okay for 5 years anyway).

This room has lots of windows so it’s not our shelter anyway :slight_smile: In fact, there’s a huge tree close by. That sucker falls and it’ll make my concerns moot LOL!