Learn how to fix a sagging roof. Find out why you should hire an independent home inspector to determine why your roof is sagging before attempting repair.
Steve in Rhode Island, welcome to The Money Pit. What can we help you with today?
STEVE: I’ve got a question about a living room roof.
STEVE: On the outside, looking at the house, there’s a little dip in the shingles. And I was told by a couple different people that you can take the sheetrock out of the living room and actually jack it up and rebrace it. But I don’t know if that would affect the shingles  to where, you know, they may leak.
TOM: Well, the first question is why is your roof sagging. There could be a structural issue here. Tell me a little bit about the house. First of all, how old is the house and how is the roof?
STEVE: The house is like 30 years old …
STEVE: … and it was reshingled  right before I bought it; about five years ago.
STEVE: And I don’t know – I don’t know why it wasn’t fixed when they reshingled it. I think they went – the previous owner went the cheap way out.
TOM: Do you think that this sag that you’re seeing could be the plywood sagging between two roof rafters, for example?
STEVE: It’s probably about a six-foot span.
TOM: In a 30-year-old house, very typically the roof sheathing is thinner than in a more modern house. Typically the roof sheathing is about three-eighths of an inch thick. And in a 30-year-old house you tend to not have very much ventilation . So what happens with those elements is that you get more sagging and delamination of the roof sheathing. The other thing that causes this type of sag is an excessively long roof rafter without proper bracing and in old house that’s not so unusual. So just, you know, doing some surgical cutting of the drywall may not get you to a solution here.
I would suggest that you have this inspected by an expert – not necessarily a roofer either. I would tend to hire a professional home inspector  so I know I’m going to get good, impartial advice – and determine what’s causing this. Is it a problem with the roof rafters? Is it a problem with the roof sheathing? Because both problems have different solutions. So I wouldn’t want you to just sort of cut it open and try to do some bracing from the underside because that may not be what you need.
TOM: You need more information. It’s not that uncommon but you need more information before you can take some action on it, Steve.
Alright, well thank you.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.