
If your roof is sagging due to water damage, you should first correct the problem leading to the sagging. It might mean replacing flashing and shingles, improving attic ventilation, and repairing your gutters. You can install angled braces to shore up rafters and correct the sagging. You can also offer more support to your walls.
How much does it cost to fix sagging roof?
Roof sag is something no homeowner wants to see because it can indicate a serious structural problem with the roof deck. A sagging roof repair can cost anywhere from $800 to $2,500 to replace one roof square of decking and shingles, minor roof sag can generate cheaper repairs.
How to go about replacing roof rafters?
- Place a jack below the break and push the rafter up until it is level with the rafters next to it.
- Cut 2×4 wood in lengths at least 1 foot longer than the broken area. ...
- Using construction adhesive on the long face of on board, secure it to one side of the rafter with the break at the center.
How to replace the rafters without removing the roof?
How to Replace the Rafters Without Removing the Roof
- Measure the dimensions of the old rafters beneath your roofing surface. Use your tape measure to record the distance of both rafter legs.
- Slide one of the newly cut rafter legs into position directly next to the old rafter. ...
- Slide the new joists into position beneath each of the new sets of rafters. ...
How to repair a sagging roof?
- Start by measuring the area of damage between the roof rafters or trusses.
- Cut a ½-inch piece of plywood that is large enough for the area.
- Glue a 1-inch piece of rigid styrofoam to the plywood. ...
- Place the plywood and styrofoam against the damaged roof decking.

Can you jack up a sagging roof?
Steps on how to jack up a sagging roof: Use a jack-and-post system to slowly jack up the ridge beam. Set up two jacks and posts so that they're evenly spread out from one another in the middle, below the roof ridge beam. Slowly jack up the roof ridge and then tighten the chains each time you jack it up.
Can a sagging roof be repaired?
Often, a saggy roof can be repaired and reinforced. To preserve your roof, it's worth hiring a professional to determine the exact cause of the sagging and take steps to correct it.
How do you stiffen roof rafters?
Reinforce the TrussesApply construction adhesive along the edge of the truss to strengthen the connection to the plywood roof deck. ... Stiffen trusses by joining them with 2x4s running from one end of the house to the other.Brace gable ends with diagonal 2x4s.Connect trusses to walls with hurricane tiedowns.More items...•
How do you reinforce existing roof rafters?
1:4111:58How To Reinforce Roof Framing – Engineering And Building RepairsYouTubeStart of suggested clipEnd of suggested clipAnother method would be to install a rafter in between the other rafters. This might be moreMoreAnother method would be to install a rafter in between the other rafters. This might be more effective on a two foot on center span. If your existing Raptors are 24 inches on center.
How serious is a sagging roof?
Is a sagging roof dangerous? A sagging roof is not only unsightly, but it can also be dangerous for your home. Roofs are designed to be straight, so sagging means that its structural integrity is no longer sufficient, and it may result in the collapse of your roof.
What causes a roof to sag in the middle?
What Causes Roof Sagging? Excessive loads or weight can weaken the structure of your roof. Common things that add stress to the roof include snow, ice, wind and the sheathing and roofing materials. Too many layers of shingles can also cause roof sagging.
How do you jack up a sagging roof ridge?
2:0910:16How To Raise Sagging Roof Ridge – Building Repair Ideas - YouTubeYouTubeStart of suggested clipEnd of suggested clipThere's a good chance that the walls. Won't fix the SAG in the roof. If you just pull them in with aMoreThere's a good chance that the walls. Won't fix the SAG in the roof. If you just pull them in with a chain you're going to need to raise them as you go with some type of a jack in post. System like
Why is there a dip in my roof?
One of the most common causes of roof issues are problems related to the rafters or trusses; therefore, giving them a good look is critical when addressing sagging, bowed or wavy roofs. They have issues for a wide variety of reason, including damage from wind storms, overloading from ice and snow, leaks, etc.
What is rafter Sistering?
Sister refers to attaching an additional framing member alongside an existing member. With roofs, this is done to improve the load value of rafters when installing roof-mount air conditioning equipment or cutting openings for skylights. In some cases, you may sister rafters to repair a sagging roof.
What causes a dip in the roof?
One of the most common causes of roof issues are problems related to the rafters or trusses; therefore, giving them a good look is critical when addressing sagging, bowed or wavy roofs. They have issues for a wide variety of reason, including damage from wind storms, overloading from ice and snow, leaks, etc.
How do you know if your roof is about to collapse?
Warning Signs Your Roof May Collapse Sections of the interior ceiling or exterior shingles that have started to sag. Windows or doors that are harder to open or that pop open on their own. Repeated or severe leaks. Sprinkler heads that have dropped under the ceiling tiles.
How do you repair a roof dip?
1:3010:31How To Fix A Saggy Roof - YouTubeYouTubeStart of suggested clipEnd of suggested clipThere's kind of drooping a little bit it's getting noticeable it's not really really bad but we'reMoreThere's kind of drooping a little bit it's getting noticeable it's not really really bad but we're gonna fix this by putting in a knee wall. Along the strong backs on either side of the roof.
How do you jack up a sagging roof ridge?
2:0910:16How To Raise Sagging Roof Ridge – Building Repair Ideas - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf you just pull them in with a chain you're going to need to raise them as you go with some type ofMoreIf you just pull them in with a chain you're going to need to raise them as you go with some type of a jack in post. System like this. So you will Jack the ridge up tighten.
How to straighten rafters?
The easiest way to straighten rafters is to jack them into position. However, the trick to this process is to do it very slowly, so it may take a few weeks before you get the rafter into a position where it is straight again.
How to keep a rafter from buckling?
To keep the rafter from buckling again, you will need to secure it with a piece of 1/2-inch angle iron. Each side of the iron should be four inches wide with the entire piece being at least two feet long. This will give some added strength and take care of any cracks in the wood itself.
Where to place angle iron on rafter?
With the joist back in its original position, place one section of the angle iron on the uppermost section of the rafter, just before the area where it is sagging or broken. Attach it to the beam with carriage bolts, but do not tighten completely.
What happens if you have a dip in your roof?
If you notice that there is a visible dip in your roof, chances are you have a problem with one, or several, rafters and you may soon be facing more issues like water leaks, bowed out walls, or your roof caving in on you.
Why is my roof sagging?
If your roof is sagging, it may be because of broken trusses or rafters that need fixing. The extent of the damage will determine the cost of the repair. If the structural beams have been damaged, prices can rise significantly; however, if only a small portion of the roof needs repairing, the cost could be lower.
How to check if a roof is sagging?
It’s a good idea to look at the roof from the street. Next, check the roof from inside the home by grabbing a flashlight and heading up to the attic. This perspective can give you an idea of the extent of the damage. Pay attention to your roof truss construction, which is the frame that supports the roof. Look for damage that includes cracks, rotting, and breakage. In most cases, a saggy roof is due to the trusses or rafters needing repair.
How long should a lag bolt be?
Tip: It is advised to use a lag bolt that is 2½ inches to 3 inches if you have a 1-inch gap. However, if your opening is slightly larger at around 2 inches, select a lag bolt that measures 3½ inches to 4 inches long.
How to check for ridge line?
Take a look at your home from the curb, and then walk around the entire house and assess the sagging ridge line, bowing, or dips.
What causes a roof to sag?
Several factors that cause a sagging roof include age, water damage, excess weight, design flaws, low-quality or incorrectly sized materials, and even faulty installation. While some sagging may not pose an immediate threat of collapse, a sagging roof can be a serious issue that requires prompt remediation.
What tools are needed to remove a broken truss?
Tip: The ideal tools for removing broken pieces of wood would be a chisel or reciprocating saw suitable for rough cutting or demolition work.
Is a sagging roof a serious problem?
While some sagging may not pose an immediate threat of collapse, a sagging roof can be a serious issue that requires prompt remediation. Only experienced roofers should take on this project due to the level of difficulty.
What size rafter ties are used for rafters?
The original rafter ties appear to be tongue and groove 3/4 x 8 inch roof planks spanning the mid level of the rafters. These are being replaced with 2x4x12 angle cut to fit at the top of the original ties and by building code here fastened near center vertically to a load bearing wall that runs the length of the house. I am also installing high collar ties and am using 3 1/2 inch structural screws.
What connects each end of a slider to its rafter pair?
Simple through-bolts connect each end of the slider to its rafter pair.
Why are collar ties kept high?
Collar ties were also kept high under the roof to give usable attic space. When combined with the use of 2x6 (or in some homes even 2x4) rafters, it was not common to see both sagging ridge lines and sagged or bellied areas in th field of the roof.
Where are the bolt holes for a sag expander?
To permit mounting of the roof sag expander, first bolt holes are drilled in corresponding positions near mid-span for each pair of sagged rafters that are to be pushed apart and back to a more-nearly-straight position. Drilling these bolt holes at the center of the rafter have no impact on the rafter's bending strength.
What is off the shelf hardware?
All of the hardware is available as off-the-shelf material. Winch, strapping, bolts, C-clamps, etc.
Will a rafter break in the next snowfall?
There is also one badly cracked rafter that will fully break next big snowfall, it is very clear to me if the state of the roof had been left once that rafter breaks adjacent rafters would be subject to the same fate with the high probability of a cascade failure.
When were collar ties used in wood frames?
Placement of short collar ties too close to the ridge was a common practice in 1960's era wood framed homes built in the northeastern U.S.
How to stop rafters from bending again?
Drilling angle iron: To stop the rafters from bending again, you need to guard it with an angle iron piece. The piece should be ½ inch; all the sides should be 4inch long with the whole piece at least two feet long. This will act as an extra layer of protection and will avoid cracks in the wood.
How long does it take for rafters to come back?
Straighten rafters can be done easily by jacking them one over the other. However, this should be done very slowly and carefully. It may take several weeks for the rafters come back in their original position.
What happens if a roof rafter dips?
This can be a serious problem in future, if not treated at the right time. This can cause roof caving, water leakage. Repairing a roof rafter in such condition is not a hurdle, but it can be a difficult task if there is no easy ...
What is the layer of protection on a roof?
Remember your roof is a layer of protection just like the earth is protected by the ozone layer . If, the layer damage you will suffer with the consequences. As soon as you see bowed roof or sagging in any corner of the roof call for the help of a professional.
How to tighten carriage bolts?
Set the iron on the entire beam. Put the jack back underneath the beam but, put it under the iron piece this time. This step needs concentration and patience, don’t panic,just follow the steps one by one and you are all set to go. Double checking the iron piece : This is the time to tighten the attached carriage bolts.
How many holes do you drill in an angle iron?
Drill the angle iron; make four or five holes in it on any one side of the piece. And to do so, you will need a metal bit.
Why is my roof sagging?
Some of the causes of a sagging roof include water damage to the roof’s surface, excessive weight from snow, and inferior quality materials. All in all, there is no need to panic when your roof starts sagging since you can repair it without breaking the bank. You can approach a professional to help you out or do it yourself.
What Could Cause A Sagging Roof?
You should always be worried every time you spot a sagging on your roof. Even though a slight sagging doesn’t necessarily point to your roof being in danger, it shows that you should act almost immediately.
How Serious Is A Sagging Roof?
It is as serious as could even result in injury or death to anyone in the house. To fix substantial damage on your roof, you’ll have to involve a construction professional.
How Much Does It Cost To Repair A Sagging Roof?
The cost of repairing a sagging depends on many factors. For instance, the cost of repair varies depending on the type of material, type of repair, type of replacement, location, and whether it’s an emergency or not.
How long does a roof last?
Although even the best quality materials don’t last forever, a good roof should last for about 15 years to 30 years. If your roof has more than 30 years, you should rebuild it to solve the sagging challenge.
What happens when your roof sags?
Eventually, it’ll curve in, leading to significant damages to the rest of your house. It is as serious as could even result in injury or death to anyone in the house. To fix substantial damage on your roof, you’ll have to involve a construction professional.
What happens if water gets on your roof?
If there is damage on any part of your roof, it’ll give water a chance to get through and weaken underlying structures.
