Advice on re-roofing and chimney

[Ramdalf]

Looking for some advice on doing a full re-roof of my 60s bungalow. There’s still a bit of life left in it, but I’m keen to get solar panels sooner rather than later, and am planning additional works at the same time (installing a new Velux and a few solar tunnels). So off the back of this, I’m engaging with an architect to get necessary planning / PD rights confirmed with a view to implementing over the next couple of years. Picture of the current roof attached (the better looking bit is part of a relatively recent, 10 year old extension, but not sure if these tiles were new or reclaimed).

There’s a few things I’d like to get advice on:

- The architect has suggested if doing a full reroof, we could take the opportunity to update the tile style at the same time. I’m open to this idea to provide a slightly more modern look. I believe the existing tiles are Redland 49’s. Obviously the simplest thing to do is a like for like replacement, but would appreciate any recommendations on alternative concrete tiles that would provide a more modern look, without causing significant additional roof work to be needed (e.g. assuming I should stick with tiles that are a similar weight)?

- Also interested in views on in-roof (vs on-roof) solar at the same time, and if this would also influence choice of tile profile.

- The chimney needs repointing and capping at a minimum, however, the internal fire is going to be removed as part of my renovations, so am also considering the possibility of just removing this - this would only be the section above the roofline, with the below-roofline section remaining as-is (with ventilation installed as necessary). I’ve been advised that most people just go for repointing as it’s cheaper, but would be interested to get opinions on how much more costly removal would likely be - I already had a quote a couple of years ago for repointing and capping which came to around £600 ex. VAT and scaffolding.

 

[robinbanks]

I’m engaging with an architect

An architectural technician may be better value for money

but would appreciate any recommendations on alternative concrete tiles

Honestly, for the pitch your roof is, just pick any you like the look of; they'll be similar enough in all other parameters. Are you considering an insulation upgrade as part of this work, eg to make the loft A more usable space?

The chimney needs repointing and capping at a minimum

Delete the chimney. Last thing you need is a big hole in your living space drafting your heat to the outside world and letting moisture in with no fire any more to help get rid of it

it's nearly no work at all (an hour with a hammer and chisel or SDS) to remove a chimney and roof straight over where it was. Weigh the lead flashing in to pay for the guy with the chisel

in-roof (vs on-roof) solar

in roof looks much cleaner, but there is a bit of a punch on the nose financially as the mounting system costs around double what rails cost. Far better looking end result though

 

[Ramdalf]

Thanks for the advice!

Are you considering an insulation upgrade as part of this work, eg to make the loft A more usable space?

Yes, I think the previous owners just did the extension as cheaply as possible - it’s just bog standard membrane under the tiles, and as for the old section of roof, its very old felt that’s rotting away. The loft conversion part really struggles with overheating in summer, so thinking of taking the opportunity to upgrade to a good quality insulating membrane (e.g. TLX Gold) throughout as part of the reroof.

it's nearly no work at all (an hour with a hammer and chisel or SDS) to remove a chimney and roof straight over where it was. Weigh the lead flashing in to pay for the guy with the chisel

Yep, this was my first instinct too so surprised I’ve had feedback saying it will be more expensive. The quote I got was for repointing the first few courses of brick, redoing the top and capping. But in my mind leaving it does mean an ongoing need for maintenance.

in roof looks much cleaner, but there is a bit of a punch on the nose financially as the mounting system costs around double what rails cost.

This is a useful insight, as often what I’ve read suggests it’s a no-brainer to use in-roof vs the extra cost for tiles, so good to know there’s hidden extra costs.

 

[robinbanks]

TLX gold is a multi foil that won't alone achieve the required U values to meet building regs. Used solo it performs about the same as 33mm of PIR, but let's be kind and say it's equivalent to 50mm. A roll of TLX gold is about 180 quid, and is 12sqm. A sheet of 50mm PIR is about 3sqm and £20. Four sheets of PIR would hence cover the same area as a roll of TLX and be less than half the price

I'd reconsider, and not just because i think multifoils are snake oil. As you're renovating a thermal element, you'll need to achieve a U of 0.18, and that's around 110mm of PIR..

 

[Ramdalf]

Thanks, yeah I might have been unclear - there actually already is PIR board insulation that was added as part of the loft conversion that was put in, and I think it (just about) meets the minimum requirements. Attached some pics from both the eaves of the conversion where the “old” roof is (rafters only seem around 9cm deep here) and the “new section’ (around 14cm deep):

Unfortunately I can’t see further up as the sloped plasterboard ceilings are right up against the rafters, but assume this is what there is behind that too, as I used a thermal imaging camera last year and saw no noticeable difference in heat leakage, plus the extension did get BC sign off.

The old part of the roof that doesn’t have the conversion has 300mm rockwool which I added a couple of years ago. So the idea of the multifoil is just to try and improve things further within the loft conversion (I understand it’s particularly good at keeping heat out due to being better at dealing with radiant heat).