Care, maintenance and repair are decisive factors which determine the durability of a thatched roof. Preventive care and maintenance is of great importance for a roof. Proper care can help to defer costly renovation. If damages from birds or storms occur immediate action very rarely costs much. A crack in the masonry of the ridge is easily fixed.
However, if you fail to react water can penetrate at the affected places. In the course of time the amount of money needed to mend the damages will multiply and unpredictable secondary damages might occur.
Algae, moss and fungi are considered to be the main cause for damages on thatched roofs or for their premature ageing. That is why in the last years the control of algae and, to a minor degree, as well of moss has become a part of the maintenance works.
General Care and Maintenance of a Thatched Roof
In the course of the overall care of a thatched roof it is advised to clean the roof and to re-tighten it once a year. The better a thatched roof is cared for and the better it is maintained, the more durable it will be. A roof dirty with fir needles, leaves, moss and algae needs more time to dry than a clean roof. The wet, damp condition of the roof does in turn promote the growth of fungi which feed from cellulose and thus decompose the thatching reed. Timely and professional maintenance will multiply the lifespan of a roof. That is why in the long run the maintenance works are less expensive than they might seem to be at first. The opposite is also true. A lack of care will always have a negative effect on the longevity of the roof.
The following measures can help your thatched roof:
Cleaning a Thatched Roof:
- Cleaning the thatched roof
- Redressing the thatched roof
- Controlling algae and moss on the thatched roof
- Trimming surrounding trees
A thatched roof has to be cleaned by hand. With help of different types of rakes the roof is freed from leaves, fir needles and moss. The easiest way to get rid of moss is to wait for a dry spell. The reason is that under dry weather conditions the moss loosens its grip on the reed. It is a common misbelief that the removal of moss damages the thatched roof. If the thatched roof is cleaned professionally only the butt ends of stalks can fall off that have been previously damaged by weather exposure. Also the assumption that harking spreads the fungal spores is objectively wrong. Reed, being a natural building material, contains per se a certain amount of fungal spores. If fungi can actually develop depends on the spores finding ideal living conditions.
Re-dressing the Roof Covering:
With the help of a legget the reed stalks are re-dressed.
Protecting the Thatched Roof from Excessive Tree Growth:
It is also necessary to restrict the growth of trees and bushes around the house. Trees and bushes shade the thatched roof and thus interfere with the drying effect of the wind and the sun.
Trees overlapping a thatched roof collect rain and dew and drip off onto the reed. Permanent dampness and moisture is the consequence which encourages the growth of fungi. Needles and leaves from trees should be removed once a year.
Controlling Algae and Moss:
You can learn more about the control of algae and moss on thatched roofs in the section: Controlling algae and moss on thatched roofs.
Controlling Algae and Moss on Thatched Roofs
The drier a roof is, the longer it will last. Mainly the wind and the sun are responsible for the „natural drying” of the roof. So, if a roof is not exposed to these two elements it cannot dry efficiently and the probability of the emergence of an algae film increases.
This layer can hermetically seal the surface of the roof and causes the roof to stay wet for longer. A reduced lifespan of the roof is the result. That is the reason why it is essential to try to control the growth of algae. Under dry conditions an algaecide can be applied
The controlling agent is applied on the roof by means of a spray gun (avoiding high pressure). It kills algae and moss and as the thatched roof will be drier on average the fungi will lose their means of existence.
Measures exclusively aimed at the fungi would at best fight the symptoms but not the cause for their growth. This procedure is not expensive and is worth the while as you can save money with regards to necessary renovations and as it will make your roof last longer (an additional 10-15 years). A welcome side effect is that the roof will look better.
If the algae are not removed in time you will easily spend ten times more on renovation works. After performing maintenance works an additional protective treatment has to take place. Should you fail to do so the remaining moss and algae will need less than a year to recover and again spread over the entire roof.