Roofers - Advice From The Builders Out There

Concrete tiles don't become porous. Its a myth commonly spread by scammers selling spray-on coatings and other garbage to con people out of their money. Concrete plain tiles do wear very thin eventually and some clay tiles spall and delaminate with weathering but by that time the roof is probably due for recovering anyway.
The sarking felt is there primarily to keep the roof watertight while the tiling or slating is underway and to protect from rain and especially snow being driven under ill-fitting roof coverings like pan tiles and old hand-made plain tiles by the wind, and to provide additional protection if a slate or tile is blown off in a gale.

Bitumen felt doesn't last very long before it starts to perish and there no real need to worry if its looking tatty, especially if you've got concrete interlocking tiles fitted.
What kills a roof covering is nail sickness which is when the nails which hold the battens and slates or tiles on rust away. If the batten nails are all good and the battens are not rotten, don't worry about the felt.
Its much better to have modern breathable membrane instead of felt. Its insulative, doesn't break down and allows water vapour from the roof space to escape but unless your money is burning a whole in your pocket I wouldn't rush to recover your roof just because of the felt. If its the original roof which I expect it is if its only a 1960s house, the nails won't be galvanised or the battens treated and its only a matter of time before they dictate a re-roof.

If you do decide to re-roof, do yourself a massive favour and while the roof is open spend some extra and fit PIR insulation board between the rafters. Its a far better way to insulate a roof than relying on loft insulation alone and prevents condensation in the roof space. Vent tiles or gable-end air bricks do need to be fitted though.

 

interesting. we need a new roof. concrete tiles. told they where pourus . hmm. been told Spanish slate is the recommended alternative.

 

Leaking valleys, that what you've got. Could be perished lead (if its a lead valley) could be that the little cut valley tiles which often have no nail holes and rely on mortar to hold them in place, have slipped.
If its a lead valley and the lead is perished there could be a fair amount of stripping to replace it as well as some scaffolding and you have to decide by assessing the condition of the rest of the roof - the timbers and the nails - whether its a false economy, even if it is inconvenient, to do a patch repair or whether its time to bite the bullet. Only you can decide. Best to get a few roofers to look at it and decide where to go with it.
When you get to the point of making stop-gap repairs with a mastic gun you could be fighting a losing battle..

 

As above, concrete plain tiles can wear very thin but I've yet to see one of normal thickness that allows water to soak through. Interlocking concretes are very thick for both strength and weight which is necessary to keep them on the roof. I haven't seen them wearing thin. They are very good at growing moss though and that holds a great deal of water like a sponge and it can creep between the tiles by capillary action. If your roof is mossy, or covered in leaves, clean it off. If its concrete plain tiles and they're worn very thin they do need replacing

Spanish slate is good and a much cheaper alternative to Welsh slate. Its nothing like as nice though. Geologically its much younger than Welsh and not as close grained so Spanish slates are often cupped and curved and rarely lie flat like hand-split Welsh. That's one of the reasons for the widespread use of tail clips rather than nails for fixing slates nowadays. Spanish slate wouldn't be my first choice in very exposed locations because of the way the wind can catch them. They are still good slates though and look nice and they're a lot cheaper than even good second hand Welsh. (You don't even want to think about the cost on new Welsh). New concrete interlocking is cheaper still and tough and durable in exposed conditions but not as pretty as slate.

 

@Birdie you always seem to be involved in the roofs? !

 

cool cool cheers folks. it is the original roof.and mossy right enough. about 70years old. had some repairs done, but its deffo coming. along with all the roughcast, the gutters, the chimney, everything. give us a quote.
yip fancy some proper slate. and yip, heard its v.expensive. i live pretty much on top of a slate mountain funnily enough. wounder if i could dig some up.

 

cool cool, forewarned an all that. need to do something fairly soon to make it affordable with a remortgage

 

If you are having the roof removed and replaced, you might consider getting a loft conversion. It costs considerably more, obviously, but the loft conversion job includes replacing the roof and insulation anyway; plus it gives you more room and increases the value of the house.

 

Grass and stones Fin, that's all you need.

 

Concrete is porous, Place these tiles in a tank of water for a week and they shall leak. This is how the scammers can swing it by telling the truth and lies at the same time!

 

Agree with everything Gimlet says....i would say for the cost of the tiles its worth getting new anyway....we did ours a couple of years ago and did the work ourselves (me and my neighbour). We stripped the lot off in a weekend and had the felt (green 50 year warranty stuff - i forget its name, not Tyvek - the other stuff). Again as Gimlet said we insulated the lot while it was off. Made it much easier. Once its felt/membrane is on you can to a certain extent take your time...

The main reason we went for new tiles was we could flog the old ones (which went to the cost of the new tiles) plus if you wanted to keep the old ones and take the roof off loads would get cracked damaged etc etc...

 

The other thing is - get a discount for ordering the whole lot from one roofing place if you can....my nextdoor neighbours daughters, husbands brother (handy to know someone) got us all the roofing materials for ours at cost....from what my nextdoor neighbour was telling me they mark stuff up roughly by 40%! (almost dropped a tile when he told me that) so they should be able to do something on the price if your buying a load of stuff at once...

 

Nothing to add here, Gimlet has just about covered it all.
Steve

 

Have you considered solar roof tiles or popping in a solar panel while you're at it ?