Thatched roofs are nice to look at, but they’re hardly the most versatile shape. Is there anything we can do about this, and, if so, what will happen if a thatched roof is flat like a building? In short, a thatched roof wouldn’t work properly if it was flat like roofs on other buildings.
This is because it needs to have a pitch to be waterproof, whereas water-resistant materials don’t.
To understand why, let’s dig into this a bit further.
Can Thatched Roofs be Flat?
Thatched roofs can’t be flat because they need to have a pitch to be effectively water-resistant. By pitch, we mean the angle at which the roof is built.
Pretty much all roofs have a pitch, other than, obviously, flat roofs.
A thatched roof has a pitch of between 45 and 55 degrees. In the UK, this is more than enough for it to shed rainfall, although other parts of the world have steeper roofs if they have more precipitation.
But why do thatched roofs need to be pitched?
The pitch of a thatched roof is what helps it shed water. On its own, thatching material isn’t really waterproof. Some water soaks into the top layers of thatch, but most of it runs off.
This is simply gravity doing its thing, combined with the thickness and density of the thatching material.
So, the thickness of a thatched roof, along with its pitch, is what makes it waterproof. Without one or the other (or both) of these factors, a thatched roof simply wouldn’t work properly.
What Will Happen if the Thatched Roof is Flat Like a Building?
If a thatched roof were flat, water wouldn’t drain away. This could lead to 2 main problems:
· Water sits on the thatching material, which would cause it to rot because it wouldn’t dry out easily
· Water would be able to make its way into the house because the roof isn’t draining it away properly
This is because, as mentioned, the actual thatching material isn’t waterproof. While the individual reeds or straws are, a bundle of them will let some water through.
Compare thatch to the materials used for flat roofs. These could be PVC, rubberised asphalt, bituminous membrane, or something else. Importantly, these materials are all naturally waterproof, which is why they can be used on flat roofs.
Even so, if you look at a flat roof after it’s rained, you’ll see puddles of water on it. This is because a flat surface isn’t good for draining water, so it just sits there until it evaporates.
While this is fine for something like rubber, a natural material like thatch will rot pretty quickly.
Final Thoughts
So, there you have it, what’ll happen if a thatched roof is flat like a building. Although it’s a reasonable question to ask, considering the concept of a thatched roof is several thousand years old, it’s fair to assume we’ve got the technique sorted by now!
