Hi all...i have just aquired a house in Bulgaria and need some advice please....
The roof tiles are of the 'half pipe' type, all piled on top of each other and not fixed down as is the tradition in much of Europe.
I am replacing the tiles with interlocking clay tiles which will be nailed in place. The woodwork all looks in good condition, so i plan to keep as is apart from replacing battens for new tiles. However, the woodwork is made from round sections straight from the tree, thus making it more difficult to lay tiles straight. My question is, should i use roof felt underneath the new tiles? I have been told that it is possible to get hold of a breathable membrane (similar to tyvek i would assume) but it will be difficult to lay it on such an eneven roof, even if i double up the battens.
What are the benefits of using a membrane and what would be the consequences of not using it?
Your opinions please!

Hi wolf...well, everything is circular, straight from the tree...and all over the place! It's all sound though so only plan to renew the battens to suit new tiles. Will have to notch out and/or pack some of the 'rafters' to try and level things up!

Nag, nag, nag Wolfie, it's like having two wives!

:-D

But thanks for the pm Wolfie, I thought you would answer this as it's a wood question.........  

Well, I've lost my copy of the Bulgarian Building Regs (I lent it to a mate....) but as far as I can see your main problem will be getting the battens 'flat' for interlocking tiles.

Interlocking tiles don't like uneven roofs  

As far as the breathable felt is concerned, what does everyone else out there use?  It's approved and ok for the UK but who knows what rules they have over there?

I don't understand your statement "I have been told that it is possible to get hold of a breathable membrane (similar to tyvek i would assume) but it will be difficult to lay it on such an eneven roof, even if i double up the battens."  Breathable felt couldn't care less how uneven your roof is, it just lays there (like 'er indoors  :-D).  It's the battens that don't like an uneven roof.

Possibly the only way would be to find the highest point of the existing rafters and pack out all the battens to suit that high point.  A slow and tedious job.

Perhaps that's why the east europeans use the 'half pipe' tiles?

Can you post a picture?

"When in Rome" comes to mind  

Why do you want to use interlocking tiles?

the benefits are:

1) It keeps the loft clean, all that airbourne dust and debris will make a loft and its contents very dirty over time.

2) It's a second line of defence against leaks.  If a couple of tiles blow off during a storm the felt acts as a temporary membrane hopefully sending rainwater down into the gutters.