Every mortar detail on a roof is a maintenance item with a countdown on it. Dry-fix systems replace that mortar with screwed clips, batten straps and ventilated rolls, so the ridge, hips and verges are held mechanically. There is nothing to crack, nothing to fall out in a gale, and the ridge line ventilates the roof space at the same time.
What a dry ridge actually is
A ventilated roll is fixed along the ridge line, sealing against the top course of tiles on each side while allowing air out of the roof space. A ridge batten is fixed above it, and each ridge tile is screwed down through a clip into that batten. The result holds mechanically rather than relying on the bond of a mortar bed.
That ventilation is not a side benefit. Warm, moist air needs a way out of a roof space, and a ventilated ridge combined with clear eaves airflow prevents a great deal of the condensation damage we get called to.
Dry verges and dry valleys
Verge units clip over the edge tile and screw into the batten, covering the gable edge without mortar. GRP dry valley liners do a similar job in the valley, giving a formed channel with upstands that supports the cut tiles cleanly.
- No mortar to crack on the most wind-exposed edge
- Consistent appearance along the whole verge line
- Faster to install, which keeps the labour cost down
- Straightforward to replace a single damaged unit later
When mortar is still the right answer
Dry-fix is not universally appropriate. On listed buildings, in conservation areas and on period properties where the roof is a visible part of the character, the plastic edge of a dry verge unit can look wrong and may not be permitted. A properly executed bedded ridge with an appropriate mix, or a cloaked verge tile, gives the traditional appearance and performs well when done correctly.
We recommend based on the building. Selling dry-fix onto a listed cottage because it is quicker would be the wrong answer.
Retrofitting to an existing roof
You do not need a full re-roof to convert a ridge. Where the covering has plenty of life left and only the mortar has failed, lifting the ridge tiles and converting to a dry ridge costs comparably to re-bedding and removes the problem permanently rather than resetting the clock on it.
Common questions
Is dry fixing required on new roofs?
Current standards for mechanically fixing ridge, hip and verge tiles mean dry-fix systems are the normal solution on new work and re-roofs. Bedded details still have to be mechanically fixed as well.
Do dry verges look plasticky?
Some do, particularly in the wrong colour. On modern housing they look entirely at home; on a period property we would generally recommend a cloaked verge tile or a traditional bedded detail instead.
Can I convert just the ridge and leave the rest?
Yes. Ridge-only conversions are common where the covering is sound and the mortar has failed.
Does a dry ridge stop loft condensation?
It helps significantly by letting damp air out at the highest point, but it needs a clear air path at the eaves to work. Ventilation only functions as a system.