How to fix sagging timber roof trusses

carpentryrooftruss

This is a follow up from a previous question: (Is this a sign of my roof trusses sagging?)

Do you know how to use ratchet ties (or some other method) to fix sagging roof trusses?

Here is an image of a ratchet tie in place:

So, this is a 2-storey brick veneer house, built 15 years ago, in south-eastern Australia. Carpernter 1 used some hoist from inside the house to push the ceiling up, then they put in place a hanging beam [i'm not sure this is the right term] for the left half of our roof. This didn't last long before the symptoms of sagging roof trusses began again. A few months later, Carpenter 2 came and temporarily used some ratchet ties, before putting in place some support beams [again, i'm not sure this is the right term] around the same area that Carpenter 1 worked on. This too didn't last long before the trusses began to sag again.

So I am thinking of using some ratchet ties and then just leaving them in place. This will allow me to re-adjust/re-tighten if need be in the future. Also I think I will place them all around my roof, instead of just one area like the previous carpenter. This is because the signs of sagging roof trusses are all around our roof.

The photo attached shows how a carpenter had placed the ratchet ties. But the photo only captures part of the image. I guess the top part of the image would have showed the ratchet tie over the rafter (which would be slanting at an angle here). Is this the right way to do it?

[I know people in my previous post told me to go to a structural engineer, but I am poor…we already tried some carpenters in the past, but it seems to have been a waste of money and effort with them…any help would be great guys, thanks in advance.]

Best Answer

TL;DR

You will probably compress your roof and make things structurally worse using "permanent" ratchet straps.

With the ratchet straps you are only hiding a symptom which can be seen from inside your home. It would make things structurally worse in the long run.

Look at your roof line from the outside, is the ridge starting to do something like this? Ratchet straps will exacerbate the issue.

I'm sorry but there is no easy fix. Either the roof was engineered wrong, built poorly, or someone took out a load-bearing wall.

You could try filing a claim with your homeowner's insurance. Hopefully they're willing to get this fixed before it becomes exponentially expensive and/or deadly. If you involve a structural engineer before calling your homeowner's insurance then you would have verifiable proof of the issue and the insurance would not be able to easily cancel your policy to avoid honoring your claim. Do note that this would very likely raise your premium.

One final thought:

Talk to a real estate lawyer. A 15 year old house should not be having this issue. You might be able to sue the builder or previous owner for this issue.

Related Solutions

Should I replace the roof or just fix it

Everyone has given good advice, but the ultimate decision is probably going to depend on the total cost and real time before you plan to add a full second story. I have done dozens of roofs in my time and can give you the following considerations.

A new roof is probably going to cost you around $300 to $350 per square (10ftX10ft or each 100 square feet) for a complete strip, 6 feet of ice/water shield and new 30 yr shingles. Not knowing the size of your roof and pitch, I can't give you a real good guess, but a simple 24X30 cape with a chimney, no crickets or tricky valleys usually runs around 3 to 4 grand. Any good roofer is going to insist that any damaged or rotting roof shiething be replaced while it is stripped, adding more cost. Don't count on using the old roof structure when you remodel. Raising a roof under a new wall system can be very expensive and I suspect you have an original rafter system and board sheithing. Your new roof will want to be of the newest materials and techniques such as trusses, tounge and grove sheathing, soffit and ridge vents etc. A second story is a huge investment and in my humble opinion, very wise to do it all new.

As far as possible repairs to your old existing roof, you may be able to replace some shingles in the field easily, and repair the leaks around the chinmey with a good coat of blind nailing cement or even remove a couple of feet of shingles and treat the area with Grace ice and water shield then reshingle that small area. Obviously, we can't see or judge the general condition or continued life expectancy of the existing roof. I would strongly suggest you stop the water ASAP as Tester is right on saying a couple years of water can cause you a lot of other problems. Good Luck

Should I pre-built rafter units, or build them in-place

Since you're putting a gable roof on it, I can only assume this is being built for storage purposes, not for aesthetics.

Building it with a glulam ridge beam would be more difficult, but it would be much stronger. The main issue with a ridge beam design would be lifting the beam into position. If you can manage that pretty easily, the rest would be a breeze. I'd put some ceiling joists up at either end, lift one end of the beam over one of the joists, pushing it far enough to clear the ceiling joist on the other side, like so...

B
   B
      B                 
  JttJttJBttttttttttttttJttJttJ     
  S         B                 S        
  S            B              S
  S               B           S
  bbbbbbbbbbbbbbbbbbbBbbbbbbbbb

B = ridge beam
J = joists at the ends of the barn
S = studs at the ends of the barn
t & b = top and bottom plate

... and then lift the bottom end of the beam up with some ropes. The joists will need some strength to support the ridge beam, and you'll need to be able to stand on them, so I'd use three 2x6's @ 9" OC on either end (where the outermost "2x6" is actually the top-plate of the walls on either end of the diagram) with some 5/8ths plywood on top of them. I'd toss in some temporary studs at the center point to make sure the joists hold up to the weight of two people and the ridge beam. Once the beam is in place, put in the ceiling joists and plywood on top of them to make walking around easier (and to create an attic for extra storage,) then put the rafters up.

Grab some metal brackets for the joists, rafter heels, and rafter/ridge connections (it'll cost you an extra $125, but it will make the structure a lot stronger) from a HI store and your little barn thing will be able to withstand some nasty winds.

Best Answer

Related Solutions

Should I replace the roof or just fix it

Should I pre-built rafter units, or build them in-place

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