Roof Replacement

[thebadger7]

Hi all. Looking for some advice on roofs. Need to get a new roof so trying to get clued up.

• Current roof at end of life - cement (possibly asbestos) tiles with bitumen underlay.
• Dormer windows need releading - bad state
• x2 attic rooms get v hot in summer and cold in winter - need to insulate
• Damp patches around top of both chimneys all winter. Had left one (from rear) repointed and new lead flashing but didn't help. Maybe it's the brickwork, which is in pretty poor state. We won't ever use fires so we could remove, but they do add to character I think.
• One room has sheepswool insulation at rafter level with lime, one is historic lath & plaster with no insulation.
• Guttering - what's best? I like the look of cast aluminium

Historic England advice suggests wood fibre sarking boards over rafters might be a good option, but this will raise roof level. Would we need planning permission? Getting a heritage firm to do it would be difficult though.

Not sure what best option for dormers would be given how small they are. Alternative approach seems more of a standard re-roofing job, and then insulate internally at rafter level (sheepswool between rafters with wood fibre under). I don't think this would be as effective at preventing summer heat gains though.

Any help much appreciated - I don't know who I should be speaking with? Roofing firms I've spoken with haven't a clue about old houses.

 

[malcolm]

I had my roof done and my bedroom is currently in an attic room. I made some poor choices. I wanted to preserve the lime and lath ceiling and there was only room for 40mm celotex between rafters to have a good air gap above for ventilation. That's not really enough and roofers weren't too fussy about fitting it. Whatever insulation you go for there needs to be a very well ventilated space above. There will be leaks and leaking hot air from inside the house will condense on anything cold it finds above the insulation and start to drip water back down.

I went around with a laser thermometer and found the Velux window was like a furnace sitting at 40C I've put a sun screen on it and it is a lot better. Details matter a lot so worth doing something with the dormers.

I doubt I would apply for planning for a small raise in the roof line to accommodate some insulation.

 

[thebadger7]

Thanks - makes sense. I guess using vapour open insulation materials will help mitigate any condensation risk - and if we insulate above the rafters then the timbers will be on the warm side