Insulating under tile roof.

[clayton]

My home is extremely cold during the winter time, while I have floor insulation in the loft space and the dreaded spray foam at the top, the roof has no felt at all.
With the design of the roof everything below the red line in the prictures is inaccessible, would it be worth lifting some tiles and inserting PIR board or Rockwall slabs ?

Thanks.

 

[Deluks]

It would be cheaper and easier to strip it back internally and insulate properly.
The cost of scaffolding etc and potential broken tiles. It'll be a pig of a job and you likely need new battens too. Basically a strip and reroof! Although at least you might be able to get some felt on.

 

[robinbanks]

Adding felt will do nothing for insulating

If you have loft floor level insulation (how much) and loft ceiling level insulation, and it's effective (no freights in the loft space) it would seem like the problem is elsewhere. If the floor level stuff is poorly installed/thin it should be improved. If there is a draught in the loft then the ceiling level insulation is doing little for you

 

[clayton]

The loft area has about 250mm of insulation,I've taken a few tiles off the back of the roof to view whats inside.

 

[robinbanks]

What's underneath the ceiling the camera is looking at, at 00:00:26 ?

 

[clayton]

What's underneath the ceiling the camera is looking at, at 00:00:26 ?

That would be the living room.