Why might hip tiles be sagging?

[5pitfire]

So the bottom-most dry-ridge hip tiles appear to be sagging, along with the fascia, gutter and soffit. Looking in the attic, the rafter appears dry and solid (although I’m not able to see to the very end of the rafter).

What lies underneath the hip tiles, and why might the corner be sagging?

I'm wondering whether this is something small which could be corrected, by me, hiring a mobile platform for a weekend - or whether I should have scaffolding erected?

[Lotobear]

there's quite an overhang/cantilever to the eaves and hip rafter - could simply be creep deflection of the timbers over time.

what was the original covering (lighter than the concrete tiles)?

Edited by Lotobear on Monday 20th October 12:53

[wolfracesonic]

Probably that ^ Looking at the picture of the house in the background with the red roof, they look like they could be asbestos slates, which your house may have had, far heavier than the concrete you have now. Has it been like this from when it was re-roofed or has it got worse?

[Rough101]

I’m not a roofer, but didn’t descending hip ridges not used to have a scrolled metal bar thing at the bottom, I think it’s called a hip iron? Albeit I imagine that’s only for ones secured with mortar rather than individual mechanical fixings.

https://ukfixingsdirect.com/products/timco-hip-iro...

[Lotobear]

wolfracesonic said:

Probably that ^ Looking at the picture of the house in the background with the red roof, they look like they could be asbestos slates, which your house may have had, far heavier than the concrete you have now. Has it been like this from when it was re-roofed or has it got worse?

far lighter

[wolfracesonic]

Lotobear said:

wolfracesonic said:

Probably that ^ Looking at the picture of the house in the background with the red roof, they look like they could be asbestos slates, which your house may have had, far heavier than the concrete you have now. Has it been like this from when it was re-roofed or has it got worse?

far lighter

You know what I meant! I do try, honestly I do try, I can’t even blame that one on autocorrect

[Lotobear]

wolfracesonic said:

Lotobear said:

wolfracesonic said:

Probably that ^ Looking at the picture of the house in the background with the red roof, they look like they could be asbestos slates, which your house may have had, far heavier than the concrete you have now. Has it been like this from when it was re-roofed or has it got worse?

far lighter

You know what I meant! I do try, honestly I do try, I can t even blame that one on autocorrect

[5pitfire]

It’s a 1930s semi. Many of them in the street still have a original pink asbestos tiles. These concrete tiles were put on by the previous owner around 15 years ago.

[Lotobear]

5pitfire said:

It s a 1930s semi. Many of them in the street still have a original pink asbestos tiles. These concrete tiles were put on by the previous owner around 15 years ago.

As alluded to above that may well be a factor as concrete tiles are much heavier that asbestos slates.

[Busa mav]

Looks like the wall plate has rolled, allowing the hip rafters to to push out a tad.

We had the very same detail on our 1930 s house , with the same result .

It s common where the rafters / ceiling joists are not linked.

Might be worth getting a few straps on top of the plate to help hold it and stop further twisting , along with bolting a timber to the rafter feet ( every 3rd) and fix them to the ceiling joists.

[Lotobear]

Busa mav said:

Looks like the wall plate has rolled, allowing the hip rafters to to push out a tad.

We had the very same detail on our 1930 s house , with the same result .

It s common where the rafters / ceiling joists are not linked.

Might be worth getting a few straps on top of the plate to help hold it and stop further twisting , along with bolting a timber to the rafter feet ( every 3rd) and fix them to the ceiling joists.

You're describing roof spread but I don't see any evidence of that in the OP's photo

[Busa mav]

Yes, to me, the plate doesn t look to be sitting square on the wall, the mortar bed under , looks to be unusually large, suggesting it may have been added .

I blame the photo , or it may be my eyes

[Magooagain]

I would say it s something to do with the fact that there s a corner window there. And I m imagining that whatever load bearing lintel/beam above has moved somehow.And yes that plate looks as if it s rolled some.

Edit to add it could be historic,so before the tiles were replaced.

[Little Lofty]

As mentioned, concrete tiles are far heavier (or lighter ) than manmade slates. I’ve seen a few hips badly deflect but usually on plain tile roofs. A structural engineer will design a fix. A roof replacement requires building regs for this reason.

[Lotobear]

...however the heads to the corner window are level relative to the eaves (which has dropped) - the corner window will also incorporate a 'bay pole' at the external angle/intersection - a concealed structural corner support for the lintel so the window lintel is not in fact cantilevered as might appear to be the case.

The wallplate does look like it has rotated slightly but they always do over the years on these 'untied' hipped roof constructions. If roof spread was in play there would be evidence of this by way of cracking to the external walls and significant deflection evident in the main roof planes (IME)

PS: to Magoo

[5pitfire]

Busa mav said:

Yes, to me, the plate doesn t look to be sitting square on the wall

Thanks so much. Is this the plate you're referring to?

Busa mav said:

the mortar bed under, looks to be unusually large, suggesting it may have been added

Is the mortar bed visible? I'm trying to visualise how it's built underneath the tiles...

[wolfracesonic]

Magooagain said:

I would say it s something to do with the fact that there s a corner window there. And I m imagining that whatever load bearing lintel/beam above has moved somehow.And yes that plate looks as if it s rolled some.

Edit to add it could be historic,so before the tiles were replaced.

It could be connected with the window, specifically when the original timber(?) was replaced with pvc and a new, I’m guessing, aluminium bay pole was installed by the skilled hands of the pvc window fitters; things may have settled a little. I wouldn’t lose any sleep over it OP, the roof is not going to suddenly collapse.

[Magooagain]

wolfracesonic said:

Magooagain said:

I would say it s something to do with the fact that there s a corner window there. And I m imagining that whatever load bearing lintel/beam above has moved somehow.And yes that plate looks as if it s rolled some.

Edit to add it could be historic,so before the tiles were replaced.

It could be connected with the window, specifically when the original timber(?) was replaced with pvc and a new, I m guessing, aluminium bay pole was installed by the skilled hands of the pvc window fitters; things may have settled a little. I wouldn t lose any sleep over it OP, the roof is not going to suddenly collapse.

I was also wondering that but thought they would have left the original corner support there and built pvc around it like.
As someone said, it’s not going anywhere. That plastic end piece though!

[Busa mav]

5pitfire said:

Busa mav said:

Yes, to me, the plate doesn t look to be sitting square on the wall

Thanks so much. Is this the plate you're referring to?

Busa mav said:

the mortar bed under, looks to be unusually large, suggesting it may have been added

Is the mortar bed visible? I'm trying to visualise how it's built underneath the tiles...

No , it’s the timber plate visible from within the loft, sitting on the brickwork

[Busa mav]

Personally, I would leave as is .
I did strap my wall plate down as recommended by the structural engineer I regularly worked with , but nothing else .

Our house , had the same detail and showed the exact same sag on each corner as your pics, we had the same sort of overhang as you too.