Push up on the plywood until the foam is touching the underside of the roof decking.
How to fix roof deflection.
Now imaging walking halfway across the span.
There is evidence of some deflection and distortion to the main frame.
That s how to fix a sagging roof.
It often occurs next to a roof penetration such as a chimney or dormer or at the edge of the roof as in the photo above and is easily verified by checking the area in the attic.
The board will sag.
I have become convinced through research and interviews with contractors and repair type folk that some of the deflection is due to improper installation practices by the installers of the roof sheathing.
Got bounce appeared in the august 2012 issue of prosales and dealt with mitigating floor deflection in new home construction.
Dry fix vs mortar fixing of roof tiles to comply with the mortar changes in bs 5534 almost all projects excluding heritage sites should use dry fix as the best alternative to mortar.
Next place your piece of plywood and styrofoam foam side up against the damaged roof decking.
I believe whatever the roof issue is it must have an impact on the home reliability whether it would be the roof shingle life sheathing life rafter life or as it seems in the picture of snow on the roof heat loss through the roof.
The original roof plane has deflected slightly over the gable end.
Note it gives the allowable deflection based on a fractional span quantity so a larger denominator will yield less deflection.
I have been seeing or at least noticing more and more of this type of deflection in roof lines lately mostly in newer construction.
Chapter 3 of the international residential code irc provides the maximum allowable deflection for a given structural member floor roof wall etc.
Deflection is the actual change in a form due to load.
After that use a piece of lumbar strapping to keep the plywood in place until you can get a roofing repair expert to fix it.
The pictures showing the roof deflection and the roof picture showing areas without snow look like they would be close to overlaying on each other.
This is probably due to failure of timber gable ladder and will need to be monitored.
Imagine a 2 x 10 board or joist is laid flat spanning from one fixed point such as the top of a wall to another fixed point.
Roof leak leakage of the roofing that has caused rot and partial collapse of the sheathing in the area of the leak is the 1 cause of a roof dip.
Also the roof slope has sagged slightly between rafters.
Deflection is distinct from from the stress or load that causes it.
However for those roofers who still wish to mortar bed tiles and fittings we have launched two new fixing kits for the ridge and hip providing a means of providing a compliant means of mechanically fixing.
