Urgent advice needed on sagging roof on house I am buying

This is my first post, I am inquiring about a house I am buying in a couple weeks. I am concerned about a sagging ridgeline in the roof, and would like opinions and advice. I really like the house and want to buy it, its the most I can afford, but I want to make sure the roof want fall in anytime soon.

As you can see in the picture, there is a sagging in the middle of the roof as you look across the ridgeline. The attic is finished in the house, and there is a main beam that runs across the interior ridge line, that rests on the two walls. The beam is something like 4x6 or so. The house had a new roof put on three years ago, so the shingles are all really new.

Should I be worried about this? Why is it like this, especially with the main beam in the middle? The beam inside does not appear to be bent or sagging at all.

Please let me know any opinions soon, I will really appreciate it!

I should also say the ceiling follows the slope of the roof, there is no space to go look at in between the ceiling and roof of the room. But there is two corners of the rooms that are built out a little and you can see the roof from in the small (storage?) rooms.


I would have a home inspection done before buying any home. I am not an engineer so i can not really tell you anything. Also looking at the picture will not tell me anything other than the ridge line is sloping from side to side. There would have to be an inspection of the trusses for anyone to make a solid answer if this is ok. What I can say is i have seen this on many homes so it is not unusal.

I did have a home inspection done, but I wasn’t very satisfied with his answers. He wasn’t able to give me a reason as to why it was happening, and I’m not sure he would have even noticed I had not pointed it out.

Home inspectors are no more than the guy that readds how to books (maybe not even that) and goes out to tell people that they think their stuff is OK, or not.

There is no accreditation, no testing, no standards…why dop peopl beleive the schmucks?

what year was the home built? my last home was built in 1860 and had the same sag. it was just from age and im sure the crowned the rafters (which were rough sawn trees from the back yard that still had bark on them) the wrong way when it was built. 90% of the time in my area (upstate ny) it is just left to being the character of the house.

My sister has a house that is about 150 years old…one of the original farmhouses in Mommence, IL. When we tore the roof off to put the addition on, the roof deck was actual sawn trees with the bark still on. I had never seen that before, and probably will never see it again.

we see it very regularly in new york because its a very old state. my area was settled pre revolutionary war. we did a roof that had actual whole trees as rafters. bark & all.

The general rule of thumb for a load bearing member spanning any distance between supports is 1 inch per 4 feet. so a 4x6 should have a post under it every 6 feet of span. So im guessing that your home looks to be at least 24 feet wide. that means you should have at least an eight in depth in your ridge with two posts under it at 8 feet on center. Or a 10 or 12 inch member with one support in the center of the room. You could get a floor jack and crank it up to level put a new properly sized ridge support under the existing one with new posts as required and set the roof back down. this might cause the roof ridge materials to crack and then that willl need repairs. But that is the easy way out. A weekend project. Back when these homes were built the same modern standards didnt apply, and the sellers are not required to bring their house up to snuff with todays building code.

and just to clarify… your roof will not collapse… it may crack but. This is as the others have said it is a natural occurance in loder homes.

My concern with jacking up the roof is the load can cause cracking of the plaster/drywall if the load is not properly distributed. I have seen this before that is why i have posted this.


That is not a weekend project.

First off, that style house does not lend itself to jacking and putting in a new beam. You would have to gut the second floor. This would also take a weekend.

Just getting everthing up there and in place would take the major part of the weekend.

It would also take several days to jack it back into place. Jack it in place is a slow process. Everthing needs time to move. Otherwise you will have cracking and buckling.

You also need to know what to watch for. Going to fast can pull joints apart. This can cause more damage in the long run.

The dead load on that roof in the picture is about 30 pounds per square foot.
A 1 inch piece of plywood laying across 6 joists with a 2x12 plank across that with a pipe jack will most certainly lift that ridge long enough to get a Strut underneath it until the new member is in place.

Sure you may have to retape your drywall at the ridge and make a patch or two.
I have done it with a 6 lb tile roof on it and added a purlin to each span in 2 days. ( my house )
Im not saying HE should do it.


Sure sounded like it.

Or were you suggesting he get a contractor that works weekends?

Lefty, thats what I was thinking this whole time…the top floor is finished…probably been that way for fifty years or more…I wouldnt worry about it, or, if you dont like it, then buy a different house.


I woule be careful of this. There is a good possibility that the sagg transferrs all the way down to the firtst floor due to the improper transferrence of the load all the way to the structural supporting beam in the basement. Is the 2nd floor sagging. Is the first floor sagging. Is the 1st floor celing sagging? these are all queations that you need to find out. best case scenario, there are no stiff leggs from the ridge to a bearing point (top of a wall) in the attic. In that case it is a simple fix. Add 2x4 stiff legs every eight feet

Possibly the second floor celing joists are over spanned and the roof load is being transferred to them. Thus by the celing joists sagging the roof is giving too.


A house that narrow with that roof on it, isnt going to have any weight transfer problems. Just an over spaned ridge. somebody probably took a wall out upstairs and it deflected. Seems simple enough to me. Dont over complicate it, just fix the dang thang. or dont buy it.

This looks like the dormer[window area] was added on and upon doing so some main supports in the center were compromised.If so a minor problem at most.The second floor appears to be an addition also.which could have been the problem from the get -go.I would dismantle the entire second floor and rebuild with a new clearstory making this possibly the best looking house in the neighborhood.

SETTLING FROM AGE,ALSO THIS COULD HAVE HAPPENED when they built the dormer,you have to see how far the sag reflects down into the structure-usually not a problem if only the roof shows the sag–plenty of tree bark rafters in nyack(the house you liked aaron),spring valley,and haverstraw(founded1666)-we call those houses pigs,but a lot of times they`re stronger than new construction-not as well insulated though

So what you’re saying is if you want it done right, get it done in 1666? :wink: