Dry ridge system. Any good?

Furts

malc_b wrote: »

I believe building regs should enforce it but they didn't seem that interested to me. One advantage of dry ridge is that you can vent from the ridge which helps keep the loft dry. This is recommend even for breathable underlays.

BTW on a new roof latest standard is to double fix all tiles at edges and single fix all the rest. This comes from standardising our building regs with Europe I believe. Europe's view is wind speeds are higher and buildings not as strong or some such hence the need to improve roof fixing.

My current roof, with add insulation at ceiling level has seen this issue. What air leaks into the loft is warm and damp to rises to ridge where it cools and condenses. Vents at the eaves allow cold air to flow in but being cold it stays under the warm air so doesn't help the condensation under the ridge. To cure this I've inserted polystyrene wedges in the (old) roofing felt.

30 years ago Redland were making substantial, solid ridge ventilators, so there was no need for dry ridge to create ventilation. They were marketed as gas vent tiles. There were also vent tiles that could be built with ordinary roof tiles. So again no excuse for ventilation or condensation issues.

Warm, stagnant air trapped in the upper part of the roof did become an issue. But it never needed to become an issue. Had builders and developers used common sense, good practice, and the available products then bingo, no problems. Ignorance, cost saving, poor workmanship...all share the blame.

malc_b

Hmm, my only comment would be that, despite Furts claims that a properly installed "wet" ridge lasts forever you see ridge tiles being re-cemented all the time but you never see screws being removed and replaced with new ones. Cement might equal a screw but it is not as certain as a screw. Given a choice, personally I'd pick a dry ridge.

snowcat75

Furts wrote: »

Ridge tiles can come off, and I know mechanical fixing has been around for years. I stand by my view, for ordinary buildings, typical ridge tile failure is because of poor workmanship.

Just because a CoP has been issued does not mean anyone will be enforcing it. Add to this it will have be written in consultation with the roof industry manufacturers and one is entitled to look at it with a degree of cynicism. Further, it has given rise to cheap, poor quality ridge systems which are not going to stand the test of time.

Dry ridge has come about, and as the years go by it will be yet another maintenance issue for home owners.

I have to agree with much of what you said, I am not a builder however I am a fairly competent self builder now on my 3rd and final (I hope) property an 1850s barn conversation.

I have never dry ridged any of my property's, and my latest which is 45 degree slate roof is no exception, which is running traditional clay angled slate ridges.

This time around I did look into dry however like you have pointed out my very thoughts that the reason for there popularity was down to a general de skill of the job rather than offering any great advantages over a properly installed traditional ridge, and although I haven't been adverse to using modern materials where needed (al facials and windows with European steel gutters per example) I personally thought the appearance of a dry system would look ugly.

Furts

malc_b wrote: »

Hmm, my only comment would be that, despite Furts claims that a properly installed "wet" ridge lasts forever you see ridge tiles being re-cemented all the time but you never see screws being removed and replaced with new ones. Cement might equal a screw but it is not as certain as a screw. Given a choice, personally I'd pick a dry ridge.

Toolstation made in China BZP screws can be rusting within months of being used externally. Then there are the fools who use the wrong screws and induce corrosion, then those who use screws too short, others fixing into ridge boards that are inadequate, others with packing timbers stacked one on the other ... the list goes on.

Dry ridge has come about largely because of a lack of skills, only for these skill levels to dumb down further and often be inadequate even for dry ridge work.

tony6403

^^
I don't disagree with your views.
But done properly the fixings should be stainless steel and not zinc plated.
For example
https://www.aboutroofing.com/pitched-roofing/dry-fix-venting-roof-ridge-hip-kits/mechanical-fixings-for-securing-roof-ridge-hip-tiles.html
However you are right that inevitably there will be problems due to bad workmanship and cutting corners.
Perhaps unlikely but it will be interesting to see if insurance companies try to wriggle out of claims for displaced tiles on non compliant installations made after the new BS.

malc_b

snowcat75 wrote: »

I personally thought the appearance of a dry system would look ugly.

I can't see why you would think this. There is one plastic dry ridge system I know of. That has plastic ridge tiles so maybe that doesn't look as good as traditional tiles. Most dry ridge systems use standard roof ridge tile exactly the same as you would put on with a wet system. Typically there is a screw and bracket which clamps the end of the ridge tile but you'd be hard pushed to see that on a roof from ground level. The only other look that changes is that you have black (i.e. a gap in shadow) where you would normally see grey mortar. On the plus side you have no mortar staining on the roof tiles and no moss growing on the mortar.

Furts

tony6403 wrote: »

^^
I don't disagree with your views.
But done properly the fixings should be stainless steel and not zinc plated.
For example
https://www.aboutroofing.com/pitched-roofing/dry-fix-venting-roof-ridge-hip-kits/mechanical-fixings-for-securing-roof-ridge-hip-tiles.html
However you are right that inevitably there will be problems due to bad workmanship and cutting corners.
Perhaps unlikely but it will be interesting to see if insurance companies try to wriggle out of claims for displaced tiles on non compliant installations made after the new BS.

Give your link, say, 10 years and the neoprene washer will have failed because of uv light and the polyethylene probably likewise. The result will be loose, and suspect ridge tiles. Used in conjunction with mortar it may last a test of time, but the flaw is the joint between each ridge tile.

malc_b

Furts wrote: »

Give your link, say, 10 years and the neoprene washer will have failed because of uv light and the polyethylene probably likewise. The result will be loose, and suspect ridge tiles. Used in conjunction with mortar it may last a test of time, but the flaw is the joint between each ridge tile.

You have presumably never used the system. The rubber washers are for stopping water going down the screw I think. They aren't for tensioning. The screw neck presses into the metal V and that spreads slightly so it is the metal V that provides tension. But either way the ridge tiles are not coming off. Even if the the fixing was slack the ridge is sitting on the V of roof underneath. The ridge tile has to lift up a lot to come away. Even if there was 5mm slack all that would happen is the ridge tile could lift in wind by 5mm and then settle back. Or more likely shift away from the wind and end up slightly tilted e.g. raising the ridge tile height until it hits the fixing.

I would also presume that the rubber is epdm and that is rated at 50yr life as a flat roof material. The other plastic parts are under the ridge tile so protected from UV.

ronat42

This topic seems cold but relevant to my problem so here is a question to open it up again. Simply, are dry ridges and dry verges suitable for these high profile regents. My house bought new in 1979 has 3 dormers with these tiles and has been a maintenance nightmare ever since. From previous comments I must assume I have employed a succession of cowboys during that period and have spent close on £10K and more recently had 2 of the dormers fitted with dry gulleys by a pair who couldn't understand the need to cut the tiles at a compound angle. Right now it hasn't leaked for 3 or 4 years but I can't fit solar panels until I know the roof is sound. Any observations welcome along with suggestions on how to find a truly competent roofer.

malc_b

I have dry ridge, valley and verge on redland double roman, not sure how that compares height wise. For the ridge you have a flexi cover that goes over the ridge batten and sticks to the roof tiles. The edges are corrugated lead substitute like on a velux. It is this that seals the roof. The ridge tiles sit over this to make it look pretty and protect it from UV. Obviously you need to clean off the ridge of old mortar, moss, etc. and it needs to be dry, so you get a good stick. I' sure there are you tube videos so you can see how they go on.