Sagging

[Broughs8286]

On the right side of our roof, am I seeing some slight sagging or just seeing something that isn’t there? I can see the ridge also kicks up, not sure why. 

[joe90]

All timber moves and by the look of it the sag is minimal. At the eaves it’s quite normal (mostly with slate) to kick the last tile up slightly. Best get up in the loft and look at the actual timbers fir damage.

[Iceverge]

There's something there for sure. 

 

Beware of lens distortion making the photo making it look worse than it is. Is there any damage to the walls?  

[Broughs8286]

No damage to the walls, and no evidence of issues with the rafters on this side (opposite side to the sister rafters talked about in another post). Yes perhaps it’s minimal sag as the person above mentioned but exaggerated in the photo due to lens distortion. 

[stu w]

Good chance a cut roof , have a look in the loft and see what you can see if any rafter have pulled away from the ridge etc 

[FuerteStu]

5 minutes ago, Broughs8286 said:

No damage to the walls, and no evidence of issues with the rafters on this side (opposite side to the sister rafters talked about in another post). Yes perhaps it’s minimal sag as the person above mentioned but exaggerated in the photo due to lens distortion. 

Well there is alarm bells.. 

 

Both these posts combined make me very concerned. 

 

Why was it strengthened on one side only? 

Has that strengthening caused the other side to bow (natural timber shrinkage prevented on one side)? 

Was that the original roofing material? Slate swapped for concrete tiles?

Is there a history of problems on the rest of the estate? 

How is the ridge looking? Is it straight? 

Is the wall plate still in position, gap in the eaves? 

 

So many questions

 

 

[Broughs8286]

Yes stengthened on one side only.

 

No evidence of an issue loft side the other side of where we see a slight sag on the roof. No gaps between the rafters and the ridge. 
 

No history of problems on the other houses. Yes I believe this is the original roof material as all our houses are the same. 
 

Ridge looks straight from the loft. 
 

Should we sister the rafters on the other side just for uniformity and to even out the weight? Can we do this ourselves if we mirror the other side by size or do we need to hire professionals? If we can do it ourselves are there advisable fixings for this job? 
 

 

[stu w]

25 minutes ago, Broughs8286 said:

Yes stengthened on one side only.

 

No evidence of an issue loft side the other side of where we see a slight sag on the roof. No gaps between the rafters and the ridge. 
 

No history of problems on the other houses. Yes I believe this is the original roof material as all our houses are the same. 
 

Ridge looks straight from the loft. 
 

Should we sister the rafters on the other side just for uniformity and to even out the weight? Can we do this ourselves if we mirror the other side by size or do we need to hire professionals? If we can do it ourselves are there advisable fixings for this job? 
 

 

I just read your other post , sorry see it is trusses now rather than a cut roof .

They All look good from the photos so can't see why doubling up would make any difference as been designed for the load 

[George]

The ends kick up because the gable is masonry so doesn't settle. Sometimes changing from clay to concrete tiles can exacerbate the sag or it just happens over time. So long as there's no signs of distress in the timber and the roof is watertight, it's usually not a problem .

[scottishjohn]

looking closely at picture it wound appear the both gables are higher than the midlle 

 measurement inside from ceiling joists or wall head  to ridge in multiple places including both ends will show if it is indeed sagging

if modern house not much chance of jacking it up on ceiling joists as they will be part of the truss

and then adding more cross braces-you would need to bring up some serious timber to put across the wall head to jack against  one truss at a time 

measurement first will tell you what you need to know -

do you have any thoughts of making rooms up there ?

 you could jack up and then add sister strusses  - not an easy job or add new ones of the attic type get the roof striaght and then cut out cross braceson old ones  ones where needed and you have beginning of attic conversion ?

 maybe not enough head room though  going by picture 

 

 

I am guessing the raters are not covered in OSB  or sarking boards--just tar paper across the rafters

my guess trusses were slightly under spec for weight and this is the result 

 how old is house ?

 

[scottishjohn]

On 06/05/2024 at 19:34, joe90 said:

At the eaves it’s quite normal (mostly with slate) to kick the last tile up slightly.

you reasons on slate -- first one is you need 2 rowas at bottom to cover gaps in bottm row 

second is to slow up speed of water coming of roof 

 what they did with my house is to use grp sheeting approx 12" wide  under first row to make up the gaps --its less than 1mm thick ,so making slaters job much easier