Hello friends, welcome to my blog, today we are going to see the process of partial repair of a tongue and groove roof and Arabic tile; It is important that you understand in depth how to choose the ideal materials for this type of roof, you can visit my previous publication Materials used in roof covers . if you have any questions on this issue, and when choosing the person or contractor who will carry out the repair.

The first task will be the dismantling of the clay tiles, which will be reused later and therefore must be stored in a close but safe place in the work area to avoid breaking them.

Once the repair began, a serious roof design error was observed, which most likely led to the deterioration of the roof and its components, such as the tiles and the asphalt layer; Fortunately, the tongue and groove is in good condition as it is made of a hard and durable wood.

The serious error found is that the minimum slopes for the roof were not respected. As a rule, the minimum slope for a roof with curved tiles for an area with heavy rains is 32% or 17.7 degrees, as can be seen in the image below. found slope of this roof is 7.7% or 4.4 Degrees, thus found multiple problems due to this error.

On this occasion, the most suitable solution is to change the slope of the roof, to avoid the progressive deterioration of the tile and the mantle, and in turn of the tongue and groove, this would imply structural remodeling that would be extremely expensive.

Due to the low slope of the roof, the tile does not fulfill its function, which is to quickly channel the water to be taken to the channel, the concept of hydraulic retention time can be used to explain this phenomenon and the roof as an installation. hydraulic system or a "basin", understanding retention time as the time it takes for a drop to drain and reach a common point, which in this case is the carcass.

The retention time is so great that the humidity passes through the tile, especially at the points with the least inclination, as is logical, and as a consequence of this the tile progressively deteriorates and damages it, as can be seen in the image.

Another weak point are the overlaps between tiles, these accumulate water between them and progressively damage the tiles because they do not have a good slope, either the one above or below; This is a vicious circle that gets worse as time goes by, the tips of the tiles break or turn to dust, allowing more water to pass through when it rains.

In addition, another determining factor is the permeability of the tile, I do not understand why this piece does not make it totally waterproof, in this way the coefficient of friction of the surface of the tile decreases and it drains much easier, displacing the water towards the channel, and would avoid water absorption; This is achieved by covering the tile with a polymeric resin that makes it waterproof as shown in the image, so the tile withstands inclement weather much better, in other repairs they have given very good results.

For the repair shown, only the damaged tiles in the affected area and their waterproofing with liquid asphalt above the existing mantle were changed, since the owners of the house did not have the resources at the moment to make more significant changes such as the change of control completely, coating of the tiles, wide fixing of the tiles, among other recommendations.

The materials to be used are Sika commercial reference waterproof liquid asphalt in a Gallon presentation. Brush for your application.

Arabic clay tiles 22 centimeters wide and 18 centimeters wide and 45 centimeters long.

Finally, some fairly well-placed clay tiles look like this, because after all, both new and reused tiles vary somewhat in size and some are very close to reaching their useful life.

The clay tile roof is conceived with the idea that the tiles are responsible for conducting the water and under no circumstances should the water pass through them and get to wet the waterproofing, that is, the asphalt layer has a role of secondary barrier, one just in case the water passes.

But the reality of most roofs is as follows: as a result of a poor design, with an intricate shape without respecting standards and added to this, a mediocre installation of the tiles, it is obvious that the water will penetrate to the waterproofing, so if a worker knows that the asphalt layer is capable of conducting water without problems, the tiles are now the ones that play a secondary role but just as important, serving as thermal insulation.

This is the main reason why the operators do not make an effort to carry out a rigorous installation of the tiles that includes, in addition to the threads, applying enough mortar depending on the case, there are many things to show and explain in depth because there are infinite variations of roofs and supplemental materials.

I hope the information is useful when making a decision, do not forget to support me and we will read next time, bye.

All images including schematics, photos and models are mine