Contact us so that we can diagnose the possible causes of your dampness.
As we have seen in the inspections that we carry out, one of the main defects suffered by buildings is roof leaks. This defect is serious since it not only compromises the habitability of the houses below the roof, but can seriously deteriorate the structure of the building. Also condensations, but this occurs to a lesser extent and is due to the lack of thermal insulation.
If in the ITE it has come out that the cover may have leaks. Before repairing the roof it is necessary to know that not all covers are the same: bituminous paints for example are the cheapest, but if they are exposed to the elements it is normal that they do not last more than 3 years.
For this reason, the important thing a client must do before considering the execution and paying a builder, is to consider two important things and what order of priority is given to these two things:
- How long do I want the cover to last? Is this a priority over the other points?
- How much money do I want to spend? Will I choose the cheapest option?
There are other factors to take into account when renovating a roof, for example, energy efficiency. The energy of a building is lost by the envelope, that is to say, facades, roofs, floors, etc. I is not lost in the same magnitude per m2 of facade as of roof, the roof in general terms is the part of the envelope that has more losses. For this reason, it will be on the roof where the € / m2 of thermal insulation will be better invested.
Below, we show you a detailed summary of the different types of classification of flat roofs:
2.3. Bituminous asphalt sheets
3.1.1. Self-protected outer sheet
3.1.2. Bituminous sheet protected with a layer of ceramic pavement
3.1.3. Rubber paints as a final finish
With gravel finish (not walkable)
2.4. The Catalan ventilated roof
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1. According to the type of functionality
1.1. Not passable
It is the roof systems such as the inverted roof with gravel layer, the landscaped roof, the flooded roof, the corrugated sheet metal deck, etc.
1.2. Passable
Roof systems such as the Catalan ventilated roof, the hot walkable roof, the inverted roof with floating pavement, the inverted roof with insulating tiles are.
2. Types of waterproofing layer:
2.1. Factory formed membranes
In this article we differentiate between waterproof sheets made in the factory and on site; This distinction is relative since even those made on site (paintings or projections) have a degree of industrialization to the extent that the product (paint, liquid, etc.) is manufactured in an industry.
The fundamental advantage of industrially manufactured membranes is quality control, reducing the dependency on the skill of the setter for the quality of the membrane. Another issue is the joints, it is necessary to have a minimum of competence when making them, but for this reason, and it is feasible with these systems, it is interesting to reduce the number of joints and unions.
2.2. Butyl sheets
Butyl EPDM sheets have a very good elastic behavior, they can be placed fully adhered or only in the encounters with vertical walls and singular points. The sheets are overlapped with a special adhesive. It is not necessary to put it in contact with oil or gasoline… There are some manufacturers that can supply large surfaces without joints, we have carried out renovation works of 100 m2 continuous roofs (manufacturers could carry out up to 800 m2 without any type of union). The favorable points of this membrane are the durability (the manufacturers certify a guarantee of up to 20 years) and the benefits, and above all very interesting the disadvantageous points are its price and although much expertise is not necessary, it is necessary to have a minimum of dexterity to position it well.
Among the butyl sheets it is necessary to consider that there are also qualities and thicknesses: sprinkler of around 1 mm, thickness of 1.50 mm and thickness of 2.30 mm
Some links to producers:
Firestone
2.3. Bituminous asphalt sheets
Bituminous sheets are normally sold in long rolls of around 1 meter or 1.5 m wide. They are joined by heat welding with a torch. It is advisable to put more than one layer and reinforce the membrane at vertical meetings and singular points. It is the most widely used and well-known waterproofing system among bricklayers.
Not protected . Here we attach a link to manufacturers:
Danosa
Protected. Here we attach a link to manufacturers:
2.4. PVC sheets
Polyvinyl Chloride has many applications, drain pipes, decorative plastics, exterior carpentry, etc. It is also used in the waterproofing of terraces and swimming pools. The PVC sheet can be reinforced with fiberglass, polyester, etc. PVC sheet has the same advantage as butyl EPDM, which is that it can be installed in very large sizes, thus avoiding joints that in the long run represent weak points in waterproofing.
It also has durability as an advantage. The downside is the price compared to asphalt sheets and asphalt paints. Here are some links to the manufacturers’ pages:
2.2. Membranes formed on site
In general, the advantageous point of this type of waterproof membranes, which consists of sprayed or roller paints, is that they can better cover surfaces that are not completely regular and with complicated shapes. Another favorable point is that if there is a leak, it is much easier to locate than in non-adhered sheets (imagine a non-adhered butyl sheet on a flat roof, if water enters through a point it could be that it runs between the concrete of slopes and the fabric until a point of easy access to the interior is found; this would make it difficult to identify the defective point on the sheet)
2.2.1. Bituminous paints
In most cases called asphalt paints, they basically have bitumen or dissolved tars in their composition. They have, like bituminous or asphalt sheets, to be protected from direct contact of light and it is preferable that they are not exposed to very large temperature changes. It can be applied hot or cold. Generally requires several finishing coats and a previous primer and surface preparation.
The advantage of waterproofing using bituminous paints is that in most cases it is the most economical method. However, it has the disadvantage that a membrane is not very resistant and that it will not have an excessive durability. It does not support UV rays and must be protected from the action of the sun.
Some links to production companies:
Sika
2.2.2. Polyurea projection
The material called polyurea is one of the so-called synthetic polymers, the solution of pure polyurea is formed by the following components Polyamine and Isocyanate. It has a lot in common with polyurethane and it could also appear as an insulating material in certain variations of the product.
It can be applied hot or cold, but is usually applied hot. Applied by a high pressure spray system, this is the most common application. You can also apply the product (it is another variant of the product) cold using a trowel.
The advantages of the product are that a flexible and resistant membrane is created, which fills in the irregularities of the texture of the materials and adapts perfectly to complex shapes. The disadvantages of this product is the price of this. Here you can find links to manufacturers:
3. According to the type of system:
3.1. Hot cover
A hot roof is a roof where the waterproofing is on top (on the outside) of the insulation, or there is simply no insulation. The waterproof sheet will be exposed to changes in weather temperature.
3.1.1. Self-protected outer sheet
Repairing a roof with a self-protected membrane is an inexpensive and durable way to rehabilitate a roof’s waterproofing. The protection layer can be of many types depending on whether it is going to be passable or not.
3.1.2. Bituminous sheet protected with a layer of ceramic pavement
The waterproof layer is covered with a mortar base and a ceramic tile or other type of ceramic tile.
3.1.3. Rubber paints as a final finish
Rubber paints are an aqueous emulsion based on styrene-acrylic copolymers. Some have reinforcing fibers, or can even be applied with fiberglass meshes. It has resistance to the passage, but only for roofs that can be visited, for moderate traffic.
You can consult the technical sheet of a product with these characteristics here: Sika
2.2. Inverted roof
Inverted because the traditional position of insulation and waterproofing is reversed. The inverted roof is mainly based on the benefits provided in terms of durability by having thermal insulation on the outside of the waterproof sheet. As the membrane is protected by insulation, it does not undergo temperature changes and the progressive loss of elasticity and final deterioration are avoided.
With gravel finish (not passable)
The gravel finish protects the thermal insulation from the weather and adds weight to the insulation so that it is not lifted by the wind or the presence of water. The ballast function of the gravels is essential since in case of heavy rainfall the insulation could float on the water that runs off the waterproofing. It is important to size the weight of the gravels based on the thickness of insulation that is being placed.
With floating finish
Apart from the advantages of an inverted roof, it also has those of a ventilated roof: it works very well in hot and very sunny climates. As in ventilated facades, the finishing layer has a high capacity to dissipate the accumulation of heat that comes from radiation.
The last finishing layer (they can be ceramic tiles, concrete, etc.) is placed on some “plots” and the pieces are placed without grouting so that the water circulates through the lower layer.
The fundamental advantage is the finish: it can be completely flat with 0% slope and the absence of grouting makes it a very clean finish.
With ceramic flooring finish
The ecru ceramic is the traditional and typical finish of Barcelona, even the city’s Heritage Department requires it on the rooftops of much of the Eixample. It is a cheap finish and makes the roof walkable.
Roof garden
The landscaped roof has a final substrate where the vegetation grows. It is important that in the final layers there is a drainage with draining nodules between geotextiles before the organic substrate.
2.3. Flooded deck
The flooded deck has a highly appreciated aesthetic quality. In the flooded roof, the waterproofing is on top of the insulation, the sheet of water that is from 10 cm high. It is convenient to place a vapor barrier under the insulation to avoid condensation.
2.4. The Catalan ventilated roof
This is a traditional system of making covers. It is not used in the rehabilitation of roofs, but we have considered explaining it because most buildings from the beginning of the century until the 80s are built with this system. Surely you have seen in the facades of old buildings several holes or small rose windows in the line of the roof. These are the roof vents, essential to guarantee the waterproofing of the roof.
On top of the slab, the chamber is made by means of partitions called conejeros or palomeros, with gaps between the bricks to allow the passage of air. On these a last layer of flooring with a thickness of several. They normally have slopes around 5 or 10%.
The Catalan roof does not have a waterproofing layer, the waterproofing capacity relies on the ventilation layer (an air chamber that can be 1 meter high). One of the errors that commonly occur when rehabilitating roofs of this type is cover the ventilation openings which aggravates the problem of leaks.
Contact with us so that we can evaluate what the problem is with your roof and how to repair it.
