Got a question about concrete tile roofs

Casa Boxhead already has one of them and one thing I noticed is that the edge tiles' fastening nails seem to loosen up with depressing regularity. Doesn't seem to happen to all of the tiles but a lot of them. Fortunately I can reach a lot of them with my regular ladder but for the higher parts of the roof I'd have to call a roofer or at least a handyman with a really tall ladder to fix this.

Is it normal that you have to reset those nails pretty much at least once a year or two? We do get fairly high winds here which may not be helping.

Yes, concrete tile roofs require regular maintenance- usually annual. Tighten loose nails, replace cracked tiles, check flashings. It's a 75 year roof, but it is not maintenance free.

The good news is a loose tile usually does not mean a leak. A slipped tile or a cracked tile does. Most installations use a batten that the tile hooks over to hold the tile in place- they don't count much on the nails.

I am a little curious- are your nails exposed? Usually, homeowners can't set the nails themselves- there are a few tricks to it.

How old is your house? How old is the roof?

Not sure of the nomenclature but I think we used to use a #6 box coated ring shank sinker when I was installing concrete roofing tiles. Some construction adhesive may also be helpful for the trim tiles.

I would consider stainless steel screws.

SVreX wrote: Yes, concrete tile roofs require regular maintenance- usually annual. Tighten loose nails, replace cracked tiles, check flashings. It's a 75 year roof, but it is not maintenance free.

That's good to know. Sounds like it would be a good idea for me to have a pro check over the roof in spring then. I'm pretty sure the PO didn't bother with that and other than me doing a bunch of visual checks we haven't done much with the roof in the four years we lived here.

SVreX wrote: The good news is a loose tile usually does not mean a leak. A slipped tile or a cracked tile does. Most installations use a batten that the tile hooks over to hold the tile in place- they don't count much on the nails.

That makes sense. No visible leaks, but that's not saying much - turns out that when the roof was raised, the contractors left the old roof structure in place after removing the concrete tiles, so I haven't been able to inspect all of the plywood structure from the inside.

SVreX wrote: I am a little curious- are your nails exposed? Usually, homeowners can't set the nails themselves- there are a few tricks to it.

The only exposed nails as the ones on what TRoglodyte called the trim tiles - i.e. the L-shaped tiles at the edge of the roof. Those are the ones that seem to be working their nails out with depressing regularity. They're nailed in from the side (as well as the top, I assume - or at least hooked onto the batten you mentioned) and it's the nails in the side that work lose. Other than that the roof appears to be in good shape - no cracked tiles I'm aware of and none that are obviously lose.

SVreX wrote: How old is your house? How old is the roof?

House is about 23 years old, about 1/3rd of the roof appears to be mostly original, the rest has been worked on when the previous owners had an extension built that required raising the roof by something like 3-5'. It's pretty obvious that they reused a lot of the existing tile but all that appears to be in good shape.

SVreX wrote: I would consider stainless steel screws.

Makes sense to me - it's pretty obvious to me that the trim tiles on side of the prevailing winds work themselves lose much quicker and carefully screwing them on instead of nailing them on should be alleviating this somewhat.

Hmm...trim tiles in a 23 year old house. I was expecting you to say it was much older, and I was going to say the battens are dried out and not holding the nail...

OK, in a 23 year old house, the decking is plywood. You may or may not have hook battens. But the trim tiles are nailed either into the edge of the plywood (which sucks), or the very top edge of a 1x (which sucks).

I would add some construction adhesive to any loose tile, and screw them back with stainless steel screws. That should hold them.

Be careful who you hire for regular maintenance. BE SURE to verify they are experienced with tile roofs. If they walk on the tiles, and are not familiar with the proper ways to walk on them, they can crack the tiles and do a lot more harm than good.

If you can find a carpenter or roofer with good experience in tile roofs, it is definitely worth the investment of a couple of hundred dollars per year to maintain an exceptional roof. But if you can't find someone with good experience, I'd leave it alone. Even without regular maintenance, it's a great roof that will last many decades. A jackleg wandering around on it can easily decrease the useful life from 75 years to about 2.

BTW, those stainless steel screws should have a neoprene washer. Wood and tile expand and contract at different rates. Tile roofs move.

In reply to SVreX:

What causes so much tile movement over in the US? Snow weight and really cold winters? Tile design? Roof pitch ? It seems really strange to me that they shift so much.

Concrete tile roof is about as common as corrugated iron in australia these days, if not more so. The house im in at the moment has concrete tile and only every third row is secured by nails. The tiles have a lip on the back edge that hooks over the batton and the weight from the tile in the row above that overlaps it holds it down. We get plenty of strong wind and a temperature range of about 50°c over the year.

In reply to daeman:

The expansion happens there too. You wouldn't notice it if the tiles are installed loose.

It's mostly the sun.

But, in the OP's case, it's not expansion. It's that the nails are probably the wrong nails, and they have a less than optimum substrate. That's why I suggested switching to screws.

In reply to SVreX:

Thanks mate, what you say makes sense and would explain why we only secure every second or third row.

Do your concrete roof tiles have a lip on the back side that rests on the batton? Because tiles with that design have very little load on the nails themselves. Though I guess that could be affected with a steeper pitched roof?

When you mention substrate, are you referring exclusively to the tile battons? Or is it common place to lay a ply board skin on the rafters and then affix the battons to that

Its really interesting seeing you differences in construction materials and techniques used from country to country.

To the OP, would replacing the trim tiles with a steel or aluminium flashing be allowed in your area? One long piece of material affixed at multiple points should stay put better than a lenght of individual tiles.

In reply to daeman:

The tiles he is losing are the trim tiles, so it's not the batten. It's the fascia and/or decking materials.

Concrete roofs are not very common in the US. Slate is common in the NE, and clay tiles are common in the SW. Slate has no hook rail, clay tile is just like concrete tile- most have a hook rail.

Older homes have battens only. Newer homes use a plybiard, then usually a water barrier, hook rail battens, and tiles. It's overkill- that's the way Americans like it.

Fiber cement tiles are thin- no hook rail or batten. They are nailed.

An un-nailed roof would be unacceptable to most buyers in the US.

This must be a southern thing. I've never heard of concrete roofs up here.

In reply to SVreX:

Thanks for the education, its been an eye opener.

I've seen the L shaped trim tiles on occasion here, but more often than not, if the roof finishes at the side of a house on a pitch a barge board or flashing/facia would be used.

I've never come across a ply board substrate in a tiled roof. Most older places are just battons directly fixed to Rafter. These days it's pretty common place to lay sarking before fitting tile battons.

I don't think most buyers here would have a clue about how their roofs are constructed, let alone wether or not the tiles are nailed.

De-canoed this.  Back to a four year old conversation everyone. 

Hah, we don't even own that house anymore.