Advice on Leaky Roof in Traditional Terracotta Tiled Chicken Coop

Hello,

This is a post about a chicken coop but it's a construction issue so I've put it in this forum. It's not exactly a rainwater catchment issue, but that seemed the most relevant of the forums.

My partner and I spent the weekend building a chicken house for our Pedrês Portuguesas (native breed) chicks, which are reaching the age that they're ready to start living outside. You can see the construction the pictures attached.

It can reach 40c (104f) in summer here and I've lost chickens to heatstroke in the UK using the normal kind of wooden hutch type chicken house, so we wanted to build something with excellent ventilation. I based this on chicken living quarters we saw in France. It's essentially a lean-to with a mostly open face at the front. In the winter we plan to stack straw bales inside it to close the opening a bit more and add extra insulation.

The roof is made of sturdy wooden batons covered with traditional terracotta tiles salvaged from our ruined barn. The main issue is that it leaks. Yesterday it rained quite hard and standing inside there were a few drops coming from the bottom of the tiles. By morning all the straw inside was damp on top. I couldn't really understand where the water was coming from as it seemed to be either beading up underneath the tiles or running down them inside...

These are old tiles and although they look fine (no cracks or holes) is it possible they are compromised somehow by age? Should we replace with new ones? Our house is made with the same tiles and it does not leak. Or possibly I am stacking them incorrectly, but they all overlap and we copied how they were laid on the barn.

Is there something else we could do to stop these tiles leaking or do we just need new ones? We don't want to use any plastic or plywood (just to make things extra awkward!)

Thank you.

I have created this breathtaking illustration to show the shape of the tiles and how we stacked them. Ignore the ones in the photo closest to the camera that appear to have a weird double layer - this was just us trying to finish it off somehow on the end. The rest are laid as in the the drawing, with a bottom layer facing hollow-to-the-sky and a top layer facing hump-to-the-sky, with all the narrow ends ends pointing towards the top of the roof.

Hi,
it is difficult to say from the picture.

Is the overlap enough?
If a drop hits hard, is a splashback goint up?
Is the angle enough steep to let the water flow down, and not sit between the tiles?

hans muster wrote:Hi,
it is difficult to say from the picture.

Is the overlap enough?
If a drop hits hard, is a splashback goint up?
Is the angle enough steep to let the water flow down, and not sit between the tiles?

Do you think adding extra rows of tiles to increase the overlap could help?

I don't know what the ideal angle of slop is for tiles like these. It's shallower than the pitch of the roof on our house and barn, but I didn't think it would too shallow. I am not sure how I would increase it.

do you have any building paper that you could lay between the battens and the tiles to divert the water?

does the top of the roof need a cap?

we use very similar tiles here, they don't "go bad" so to speak, they might get licheny or mossy and then eventually crumble, but they're not leaky. If you're overlapping them the right way the water should run off, if it were me I'd go out there with a watering can and put a towel down to see if i could replicate the leak.
Did you have a storm with some wind? Even in our relatively new tile roof, when things are blowing we will get leakage, it's kind of inevitable. Inside homes here there is usually a subroof to catch this leakage, you could conceivably put something underneath to catch this leakage and drain it out (no plastic, but how bout an old raincoat, canvas, tarp, etc? or maybe just a board. Even some cardboard would work for a while, just to divert the leakage)

This looks really pretty. How about just adding a metal sheet under them?
I did mine with two metal sheets and it was ready in ten minutes.
there are several huts like this around the farm. The chickens stay in all of them, depending on which suits the weather.
I did not want to go overboard with construction so these are really simple.
Did not buy anything, these are made from various bits I had lying around.

Nice shed! I think from my memory of how my Bulgarian neighbours' shed is roofed, you might need more overlap, at least 1/3 of the tile length. I'm almost certain they stack the "ditch" (hollow side up) tiles double, too.

I have read that certain types of roofing need a minimum pitch to work, as Hans Muster suggests. Have you calculated the pitch?
A quick search came up with this:

Minimum roof slope recommended for the application of Spanish tile is 4:12, meaning a 4-inch rise in the roof for every horizontal run of 12 inches.

Tereza Okava wrote:we use very similar tiles here, they don't "go bad" so to speak, they might get licheny or mossy and then eventually crumble, but they're not leaky. If you're overlapping them the right way the water should run off, if it were me I'd go out there with a watering can and put a towel down to see if i could replicate the leak....

Some were a little bit mossy - I didn't bother to clean them besides brushing it off. They looked okay underneath. Does the moss cause damage?

Kaarina Kreus wrote:This looks really pretty. How about just adding a metal sheet under them?
I did mine with two metal sheets and it was ready in ten minutes.
there are several huts like this around the farm. The chickens stay in all of them, depending on which suits the weather.
I did not want to go overboard with construction so these are really simple.
Did not buy anything, these are made from various bits I had lying around.

Thanks - I think we will try and get a metal sheet to go underneath if we can't make them work. It's surprisingly hard to get stuff like that round here though!

Jane Mulberry wrote:Nice shed! I think from my memory of how my Bulgarian neighbours' shed is roofed, you might need more overlap, at least 1/3 of the tile length. I'm almost certain they stack the "ditch" (hollow side up) tiles double, too.

Okay, very interesting. I will try taking them all off and adding some more. They are definitely not overlapping 1/3rd, so we'll try that.

Jay Angler wrote:I have read that certain types of roofing need a minimum pitch to work, as Hans Muster suggests. Have you calculated the pitch?
A quick search came up with this:

Minimum roof slope recommended for the application of Spanish tile is 4:12, meaning a 4-inch rise in the roof for every horizontal run of 12 inches.

Interesting - I will have to work this out and see what the pitch is - thank you!

I just want to thank you all - we took all the tiles off and redid them yesterday with a double layer on the bottom, also making sure that each tile was overlapping its neighbour by 1/3rd. I also added a sheet of hessian-type material underneath the tiles, which will hopefully slow or divert any drips that do make it through.

Turns out this was just in time, as it was put to the test this morning with a torrential thundering downpour! The straw and chicks inside stayed dry this time - a great success! Thank you for encouraging me to redo it as I was really thinking these tiles were not going to work.

Edit: short video here - https://www.instagram.com/p/Cs_Wde8s442/ (for anyone on instagram) where you can see how well the roof is working now...

just in time! yay for dry chicks.

Fab! So glad it worked for you!

Now you just need some containers to catch the drips at the back!
I'm so glad you gave it another go. I always like to see people reuse materials that still have good life in them!

Jay Angler wrote:Now you just need some containers to catch the drips at the back!
I'm so glad you gave it another go. I always like to see people reuse materials that still have good life in them!

Absolutely! Next project will be a little gutter to catch the runoff and divert it to a barrel for their drinking water.