Wet Battens

[TheMrX]

Long story short, now that some of my roofing felt has been removed I can see that when it rains some of the tile battens are getting wet. There is no leak but what it looks like to me is that the capillary action of the water spreading through the tile is making the batten wet.

Should I be concerned? Or is this something that happens but is just not normally seen as the felt hides the view?

It never gets to the point where it drips, but I’m concerned that with winter approaching it might reach a saturation point where it either drips, rots the batten or spreads and rots the roof joist.

Grateful for any advice.

 

[2scoops0406]

Well, I'd say be concerned, it should be as dry as an oven.

 

[^woody^]

Its common, and it dries off.

Roof tiles are not actually impermeable

 

[noseall]

there should be no water ingress as far as the roof tiles are concerned.

is the loft space being used?

condensation?

 

[TheMrX]

Bit of a difference of opinion then.

No def not condesation. Bone dry until it rains and then you can see it gradually spead across the batten. You can also see that the underside of the tile is wet along with the mortar bedding/pointing. This also seems to spread across the underside of the tile the more it rains. Thats why I wondered if it was 'normal' capillary action. But couple of replies suggest its not.

Now I am confused!

With the constant wetting and drying isnt it more like to rot? I can see the battens are treated but don't know if the roof joists are. (only lived here 2 years, house was built late 1960)

 

[^woody^]

Keep up

This is above the felt, and the tile laths are getting wet

 

[TheMrX]

Keep up? Who?

If you mean me then as I said to start. The felt has been removed so I'm worried the moisture will travel along the lathe to the roof supports and start to rot it.

Or are you saying I shouldn't worry this is normal and it wont rot?
[/quote]

 

[^woody^]

No, the bloke above you - you queue jumped before I could post.

Why has the felt been removed?

 

[justlead1]

Hi. What pitch is the roof? Has the mortar be added since roof construction? Bedding tiles in the 60's was not standard practice. Good Luck

 

[TheMrX]

The reason some felt is removed is because I had the valley replaced.
Originally, it was made of 1/2 circular tiles (sorry don't know correct name) and I noticed a couple were cracked and the pointing at the side was crumbling. So a local builder stripped it all back and replaced with what looks like a tough corrugated plastic. Looks fine except that there is no felt about 2 foot each side of the valley now (he said it wasn’t necessary??) and as mentioned I can see that some of the battens get wet when it rains, seemingly from touching the tiles and/or some of the cement at the edges.

I'm afraid I don’t know what pitch the roof is. Other than to say steep! I’d say about 60 degrees if I’m measuring right! It’s Impossible to walk up without sliding up a few tiles, it’s a chalet style if that helps.

Incidentally I should add that when the roof tiles went back originally I did have some leaks and the builder came back several times to fix. Eventually all seemed well until the recent persistent rain.

To be honest, if the general feeling is that this is a problem then I’d rather try to get a full time roofer in to fix as although the builder has not caused a fuss coming back I wonder if it’s just not his bag.

 

[^woody^]

The job of felt is to catch any water that gets past the tiles. Whilst it is Ok for laths to get wet, now you have the potential for water to get into the roofspace.

The builder should have put felt under the valley trough. He's done an incorrect job and it should be rectified

 

[stuart45]

Its sounds like a real bodge job. Glass fibre valley troughs are the cheapest method and its lifespan is unknown. If only a few of the valley tiles were broken it may have been better to replace them. Otherwise a lead valley is much better.
He should have put felt under the trough and then lapped the other felt over it.

 

[TheMrX]

Damn! That is what I feared!