Sagging House Roof Question

[TTMotorsports]

OK so i'm looking at a small home to buy/move into and it's a good deal BUT i think that it's a good deal because the main roof of the home has a slight sag to it and roof needs to be replaced. Now I'm going to get a home inspection but what should I ask the home imspection companies to see what they should inspect to see what the problem could be AND if it is failing trusses does the entire roof need to be removed and trusses replaced and rebuilt to make sure it doesn't fail again? Thank You

 

[cvairwerks]

Could be too many layers on the roof, or a structural deficiency. Mom and Dad’s house had a swale in the roof on one end due to having a few critical joists fail and allowing some roof supports to move. Fix was to replace joists, jack rafters back into place and full length sister new wood in. This was the easiest fix from the structural guy that Dad’s contractor consulted beforehand.

 

[matt_i]

My faraway guess is there are no trusses and its an unsupported ridge setup.

A really good forever fix would be to tear off the roof and install new trusses and rebuild the whole thing and likely pickup energy efficiency as well.

But theres certainly a large cost to that solution...every ceiling would be wrecked, cost of wood products is astronomical and the labor, plus would delay any kind of moving-in.

As you survey the situation a good tool is a level that you can apply to walls to see if those are pushing out as a result of the deflection in the ridge...without the bottom chord of the triangle the deflection you see in the roof can be telegraphed to the top of the walls as well.

 

[BillK]

the main roof of the home has a slight sag to it

What exactly do you mean by this ? Where exactly is it "sagging" ??

 

[Innovate1]

You can ask the home inspector but any suggestions for fixing it is beyond the skills of most home inspectors IMHO. They may be able to point you to other people/companies that could evaluate the construction though so it's worth a shot. Might want to ask the inspector up front and search around for a good one.

Hard to say how complex or expensive the solution would be without more information. How much is the sag? Complete replacement of the roof structure with trusses is a huge job and likely not needed but I suppose it's possible.

There are multiple threads here on dealing with sagging roofs for garages. The house isn't going to be as open so jacking up the ridge and/or pulling in the walls (if that's what is needed) is going to require a few holes in the ceiling and walls. Looking at if the walls are being pushed out by putting a level on them or measuring at the top and bottom is a good start.

 

[Jlbc212]

Weight on the roof tends to push the supporting walls outward and is often visible as a sag along the ridge along the middle section of the roof. The outward push on the supporting walls is prevented by the ceiling joists. If you can get into the house take along a minimum 4ft level and check to see if the exterior walls are plumb. If they are leaning outwards it could mean the ceiling joists were not nailed adequately into the top of the walls and/or where they come together in the center of the structure. There's no easy fix in a finished house.

 

[wrenchguy]

Been hackjobed to vaulted ceiling recently.

 

[BillK]

All of the responses so far are just off the wall guesses without knowing exactly what he means by "sagging".

Is the entire ridge sagging ? Is the sheathing sagging between trusses or joists ? It it sagging at the gutter line ? Etc etc etc. I dont see how anyone can really answer without pictures or a much better description of the problem.

 

[reader2580]

My roof has a slight hump in it where the first truss of an addition is. I just had a roofing company out yesterday about a new roof and he said that it not an issue (other than cosmetic) and can't be fixed without ripping apart the whole roof structure.

 

[yeldogt]

You would have to show us a picture ...

Many old houses .... like craftsman bungalows have a wide ridge and they all seem to get a little bow in 100 years. It's normally not objectionable ... and not easy to fix if it's a bother.

If it is really noticeable -- that's a problem. Another issue is wide rafters with sagging in-between. That's normally thin OSB

 

[Innovate1]

All of the responses so far are just off the wall guesses without knowing exactly what he means by "sagging".

Is the entire ridge sagging ? Is the sheathing sagging between trusses or joists ? It it sagging at the gutter line ? Etc etc etc. I dont see how anyone can really answer without pictures or a much better description of the problem.

+1. My previous posting was directed at older roof structures that were often done without trusses. The OP mentions trusses but at this point I am wondering if it is trusses or not. Really need more information. If the sag is actually slight (really need to quantify that) and the structure is solid then it may be just cosmetic and fine.

Lots of companies want to put another layer on when reroofing. It is cheaper but adds weight and doesn't allow you to see/fix any underlying issues. If it needs new shingles I would do as much structural work before the reroof and tear off the old shingles when reroofing.

 

[firebirdparts]

I'm not sure that home inspectors really expect to get into collapsing. A lot of them are probably pretty competent at understanding framing, but that may not really be a requirement of that job.

You'd be better off having it inspected by somebody who knows why houses don't fall down. I don't know how you find a guy like that. Framing is really simple, but some people are incredibly ignorant of it. Do you know somebody that just knows how to do stuff? That's what you need.

if you did take the whole top off, honestly, it's not that much money. Not out of the question. I bet it's not failing trusses. If I was betting. I bet the house doesn't have trusses.

 

[quickfarms]

This could be nothing or a big problem

The first question is how old is the home?

The next question is what does the roof framing look like, truss or stick. If stick rafter size and spacing and length?

Where is the home located?

How many roofs are on the house?

My house is old, tax assessor found it in 1890, the roof is 2x3 at 32” on center. When we bought it there was an obvious bow in the ceiling from the weight of the roof. The roof was 5 asphalt on top of wood shingle, the riff probably had never been torn off. 13 tons of old roofing was removed and replaced with plywood over the spaced sheeting and one asphalt. Then the house was haunted for the next year as the ceilings slowly moved back to level.

The home inspector did not note the excessive roofing or sagging ceilings

 

[paredown]

<snip>The roof was 5 asphalt on top of wood shingle, the riff probably had never been torn off. 13 tons of old roofing was removed and replaced with plywood over the spaced sheeting and one asphalt. Then the house was haunted for the next year as the ceilings slowly moved back to level.

*shakes head*

What is wrong with people?

Re: old houses--we've seen some pretty light roof structures built pre-inspection; even as late as post WWII. For the last two Habitat houses, we have basically rebuilt the roof structures and added beam where necessary to get everything solid--easy enough to do when the house is gutted.

 

[Renegade1LI]

More than likely it can be fixed, I guess it depends on how good of deal the house is. Worst case a full rip off and repair or replace what's causing the problem and new roof. You could have 2 x 6 at 24" o c with 1/2" plywood and two or three layers of shingles??? Not enough info, but anything can be fixed$$$$

 

[TTMotorsports]

So the sag appears to be the main ridge in the home. It's a small 1bd 1 bath home almost like a granny house. I will esentially tear a hole in the ceiling to peak at the roof to see if it's truss or if it's a main beam and will report back. If it's a failed main beam then I would just replace the main beam with something bigger unless the wood decayed and caused the failure than upgrade if necessary. Thanks

 

[Innovate1]

So the sag appears to be the main ridge in the home. It's a small 1bd 1 bath home almost like a granny house. I will esentially tear a hole in the ceiling to peak at the roof to see if it's truss or if it's a main beam and will report back. If it's a failed main beam then I would just replace the main beam with something bigger unless the wood decayed and caused the failure than upgrade if necessary. Thanks

The ridge "beam" may not be a beam at all. Often they were 1 x or 2x pieces just to aid keeping things lined up and not supporting any weight. The weight was supported by the two rafters with the bottoms kept from spreading by the ceiling joists.

 

[brownbagg]

its properly trusses with osb. that stuff always sag

 

[justanengineer]

Ridge vent on the ends can also make the middle appear to sag since it’s a tiny bit higher.


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[pmiranda]

I don't think I've ever seen a house that didn't have some sort of roof access from a closet or hallway so you could pop your head up there and see what's going on. Have you been in the house yet?

 

[walta]

Without knowing how old the building is or how it’s built all anyone can do is guess. My wild guess is someone decided the remodel the house and opened up the rooms by removing a few walls or vaulted the ceiling.

I think you are dreaming if you are expecting the home inspector to tell you anything about the roof structure. They gloss over anything that will kill a sale because if they get a reputation for killing sales the agents stop sending them work.

Walta

 

[sjvicker]

If I was in your shoes I'd see these as my options

1: ensure the inspector sees the issue and puts it in the report then negotiate down or go for a specialist inspection depending on the results

2: assume it's a full tear off plus other random structural. Get that quoted and deduct it from their asking price

3: walk away


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[TTMotorsports]

If I was in your shoes I'd see these as my options

1: ensure the inspector sees the issue and puts it in the report then negotiate down or go for a specialist inspection depending on the results

2: assume it's a full tear off plus other random structural. Get that quoted and deduct it from their asking price

3: walk away


Sent from my SM-T560NU using The Garage Journal mobile app

OK that's my plan now as well. Next time I can visit the home I will have a contractor come out to quote a complete fix and deduct it from the asking price. If it needs less score for me worse case I got the price down for them to fix it anyways. If they don't come down the amount of the quote then I'll walk away.

 

[didit]

If the outer walls have not bowed out, it may be as simple as jacking up the roof and getting some collar ties put in place. I have seen that more than once, where someone has removed some collar ties to utilize space in the attic. Some pics will help diagnose the problem.