Can I replace tiles with felt on pitched roof

[jraspin]

I have an original rear 2nd floor extension with a pitched roof which joins the main roof. The pitch of each roof is different, with the extension roof at a much shallower angle. All my neighbours have a similar construction. Additionally, the way the roof joins the neighbour creates a slight dip either side of the party wall. This is difficult to fix without reducing the slope even further. Over the years the poor slope has caused numerous problems with water rising up the tiles either by wind or capillary action, even after replacing all the felt and tiles 4 years ago. Some neighbours have had similar issues.

The latest roofer has suggested we replace the lower roof with felt and cover as though it were a flat roof.

To be honest I'd thought of this myself but it sounded very odd. However, when it was suggested I liked the idea. Could anyone tell me what they think are the main pitfalls of such a solution. Obviously felt won't last as long as the current slate tiles but the cost to replace the felt every 15 years or so would be a lot less than the cost of maintaining the current roof. There's also the issue with how it joins one neighbour who currently shares some of my tiles. It might also look odd and affect resale value.

 

[noseall]

Felt roofs do not need replacing every 15 years.

Any chance of a piccie?

 

[jraspin]

Yes, a photo probably would have been sensible. If it's dry enough in the morning to get out on the second extension I'll get something. You can't see anything from the ground as the shallow slope hides everything. Be ready for an ugly roof!

 

[jraspin]

Roof

• jraspin
• 14 Jan 2015
• 1

Here's a picture of he roof. You can see the join with the neighbour and the ridge that messes up the tiles.

One roofer has suggested I remove all the tiles from the lower section (where the gradient decreases) and replace with a flat roof. I'm not sure how he would cut the joining tiles for the neighbour and provide them a seal. The idea of removing the tiles sounds great, but do you think this is possible?

This all came about because of the latest leak which occurred inside, just by the bottom of the slope, near the window frame. The roofer believed it was caused by capillary action and inserted 2 eave trays at C. He also fixed a few tiles and in total charged £275+vat. He's now returned, after the leak recurred, to propose removing the bottom 2 courses of tiles (I assume to properly insert the eave trays, which the 2nd roofer says were not well done and probably useless anyway) and repair two tiles at A&B which he didn't do the first time. And wants another £200+vat. I'm not averse to paying for meaningful work to be done but this strikes me as very cheeky.

 

[freddiemercurystwin]

That lower roof looks very flat, no wonder its leaking. what is the pitch of it?

If so a flat roof material would be a much better option though the junction with your neighbours tiled roof would be a little unusual. But whilst I don't think there's a particularly standard way of doing it there are some options with either a secret gutter or an upstand, or mini parapet wall maybe. I'll do a doodle later if I get time.

Any chance you could get your neighbour to replace theirs with a flat roof system too? That would be ideal.

 

[jraspin]

I'm not sure I've got much to measure the pitch. Maybe I can measure the length of the floor and then the roof elevation.

I assume if any sort of dividing barrier is introduced it would need to start at the point the two slopes connect, halfway down the entire slope. I'm not sure how that join would be made but I know next to nothing about roofing so probably unsurprising.

I have a feeling the current leak is not the result of any cracked tiles but just poor felt at the base (rotten and disrupted by the eave trays) and water is making its way up the tiles by wind and trickling down. Once the water builds up it could just find its way to the weakest point in the felt and seep into the bathroom even after the worst of the rain has passed. The leaks only occur at the point where the felt was exposed and rotten. The eave trays possibly don't connect with the felt in all places (evidence does suggest this) and so water could easily trickle under the trays. It's an idea.

 

[catlad]

Tell the roofer you are not paying him any more money £275 +vat for two felt support trays incorrectly fitted, and replacing a couple of slates is plenty.
You could remove the bottom 4 or 5 coarse of slates and ply the bottom section of the roof and then use torch on felt to seal that problem area then replace the slates.

 

[jraspin]

Thanks. I feel a bit more confident going back to the first roofer now. I've already written off the first amount so anything will be a bonus. I've always got the second roofer who I trust a lot more to fall back on (unfortunately he was away on business when the leak occurred over Xmas).