Use instructions from my page how to fix a sagging floor before you continue trying to fix the roof sagging issue.
Old house sagging roof.
Sagging rafters can lead to serious problems with the entire roofing system.
Properly built the roof of a house should be tied to the walls and the walls tied to the foundation so that the structure has a continuous load transfer from top to bottom with all elements well connected.
And in a 30 year old house you tend to not have very much ventilation.
Remedies for a sagging roof there are a number of remedies for traditional rafter style roof frames depending on the problem and its severity.
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 what happens with those elements is that you get more sagging and delamination of the roof sheathing.
Check the ceiling for sagging by attaching a string on one end of the beam and run it along the bottom edge of the beam.
Cracked rafters and trusses can cause sagging.
If the line does not continually follow the bottom of the beam and the bottom of the beam is below the line the beam is sagging.
Occasionally a house wasn t engineered properly for the type of roof that has been applied.
You will need to remove the shingles and the old decking however which means there will be an exposed hole in the 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.
If your roof s structure is unsound because of leaks or termite damage you may start to see bowing in your roof.
Typically they are lapped and then toe nailed together in its center so that the correct length can be achieved.
The old roof could have the slightest dip not easily perceptible.
Often the framing can be bolstered and beefed up internally but if the roofing material needs replacement anyway it may be best to tear off.
When the framing of the roof is put together quite frequently two of the ceiling rafters will be fixed together as this will create a much longer span.
A sagging roof line may original from the ceiling s horizontal rafters.
You can simply have the old sheathing replaced with better material when it s time for new roofing.
They just had rafters and one could be broken or sagging 5.
1 2 inch thick angle iron.
Houses built before the 60s didn t have trusses maxfield says.
Typically the roof sheathing is about three eighths of an inch thick.
If the framing is sound and problems are not found elsewhere but the roof still sags the problem might have originated because of poor installation of the plywood sheathing or shingles.
A real problem in old houses maxfield says is multiple layers of roofing.
Roof design should provide wind resistance most old homes and many not so old homes simply are not built to take extremely strong wind.
This may be problematic in winter months but allowing the roof to continue to sag can lead to greater problems such as a cave in.
