If a thatched roof is well made water will only penetrate to about 50 mm which is about 20 of the whole depth.
How often to re thatch a roof.
Lead and cement flashings coming away from chimneys and gaps where they meet the thatch should be checked and cement flashings which are cracked or broken may need looking at.
With that said there s a slim chance that you might not need to replace your roof every so often.
The thatch above windows or in a valley is often thus.
50 to 55 degrees of pitch is more desirable.
E xperience has shown that a roof structure with a minimum pitch of 45 degrees is necessary for a successful thatched roof.
Many roofs have areas near or below this minimum pitch.
As mentioned weather conditions can be very unpredictable.
Rarely is attic venting needed in a structure with a thatched roof because the natural materials breathe so well.
Although a thatched roof should last around 30 years before it must be replaced the ridge should be replaced every 10 to 15 years as it receives the most wear and tear from the weather.
But in cases where poor design or installation results in poor breathability the lifespan of a thatched roof will be reduced.
Aside from this other factors would cause the quality of your thatched roof to deteriorate e g mold.
A thickly thatched roof is not the best roof it is down to the pitch of the roof.
But this is a case to case basis.
Generally a roof should have 3 4 brushings in it i e it should be thick enough to allow 3 4 separate occasions of brushing over the years before it needs to be re thatched.
Since the dry thatch will have a longer life it s possible to strip off the top layer every ten years or so but leave the lower layers in place.
To keep your thatched roof looking great there are a few things both you can do and roof thatchers can do.
These thin coats of thatch last up to five years or so.
These are just indicative signs.
Ridges provide excellent opportunities for the thatcher to demonstrate their decorative skills so the design of a new ridge will influence the cost of its replacement.
Tips on thatched roof replacement.
As a general guide most thatched roofs need brushing ever 8 or so years.
Keep an eye on your roof throughout the year especially before and after winter you can see where about on your roof needs repair by checking the ridge.
A steeply pitched roof is of the utmost importance.
This is normally acceptable.
When should a thatch roof be brushed.
