EPDM – Uses, Characteristics, and Advantages
EPDM is a type of elastic rubber made up of ethylene, propylene, and diene that is used to waterproof a terrace, with very good results.
The material to the naked eye is a kind of black flexible rubber, similar to a car wheel, but much thinner.
Is EPDM waterproofing the same as a Butyl rubber sheet?
Yes. Some people call EPDM Butyl because they are practically the same product.
Both products are made of rubber. The only thing that differentiates them is the type of polymer that they contain in their composition.
Butyl is priced higher, but when it comes to usage, they both perform exactly the same.
Placement of an EPDM sheet for roof waterproofing.
The first thing to keep in mind is that the roof or deck must be dry and free of dirt and roughness.
It is convenient to execute a perimeter clearing, which reaches the height of the plinth (about 20 cm high).
Once clean, the waterproof rubber membrane will be placed. An advantage is that this type of vulcanized rubber is not laid with a torch, but with adhesive.
Next, the EPDM sheet is glued in strips 5 meters wide so that they do not crease.
If it is done with larger pieces, there will be wrinkles due to the slopes of the terrace (to evacuate the water).
Later it can be painted over.
We can choose between 3 types of sheet thicknesses:
1.14mm thickness: It is the thinnest and cheapest. Before placing it we must verify the cleanliness of the support. Better to 1.14mm with smooth support than 1.52mm with bad support.
The thickness of 1.52: The one that is being used the most in houses. And the workmanship is the same as the 1.14. It is also ideal for road traffic. But the support must be completely clean (I won't get tired of repeating it).
The thickness of 2.28 mm: This is widely used in the US, but it is excessive for Spain. This sheet is much more expensive than the previous ones.
Main uses of EPDM waterproofing membrane
EPDM sheets can be supplied in large modules of up to 800 square meters, without joints.
If requested, you can even order an EPDM piece cut to size, virtually solving the seamless cover.
This makes them ideal for waterproofing large surfaces, such as the roofs of shopping centers, hotels, hospitals, etc.
They are even used to waterproof irrigation ponds, ponds, swimming pools, and reservoirs with millions of liters of water, the membrane remaining outdoors for many years and withstanding extreme temperatures without wearing out.
They are also used in places where you want to build green roofs because the EPDM sheet is already anti-root in itself.
What are the advantages of waterproofing a roof with this EPDM rubber membrane?
Its duration is superior to that of bituminous blankets (asphalt sheet). It also supports
heat better, without rusting or degrading.
You don't rely too much on the skill of the workforce. These sheets are delivered by large pieces almost to measure, with the same thickness on the entire surface.
The quality of this material provides the best resistance to ozone and ultraviolet radiation.
Its market is growing unstoppably. EPDM lasts a long time. They give a 20-year outdoor guarantee.
It is a flexible and highly elastic material. It does not cause structural problems due to movements, breaks or half rounds (encounters with walls).
Instead with asphalt fabrics, pvc and other materials if you can have these problems.
You can use the quick joint system, which makes it safer: The primer is applied, and then neither the interior putty nor the exterior putty. The paper is removed and the adhesive remains.
With this system it is easy and safe to waterproof singular points: drains, corners, pipes that come out...
As it is made from recycled rubber, there is no paving breakage. When you drive a screw into the EPDM, you tighten it and it stays tight.
It has accessories for this, such as flashing, which is a kind of chewing gum that adapts and allows you to make a continuous sheet, even if you have pivots from solar panels or antennas there.
There is a system to make the EPDM passable in rehabilitation, and also with a system of recycled and ecological material: recycled rubber tiles, formed by recycling old shredded tires.
This will make it very resistant to footsteps.
Installation precautions on an EPDM sheet
Do not put it directly on concrete. The idea is to put a layer of mortar on the concrete. In the concrete, there are always ridges, little peaks.
This membrane must always be placed by specialized personnel, to avoid irreparable errors due to poor distribution of membranes and overlaps.
Its characteristics mean that its fundamental use is for large roofs. It is not usually used to cover patios or small roof terraces.
A separator geotextile should be placed between the waterproof sheet and the support, bot n a walkable and non-walkable roof.
If tiles, stoneware, or gravel are to be placed on the EPDM sheet, it is always advisable to place another geotextile and a layer of mortar on top of the waterproof blanket.
By the way, if you paint the tiles with white deck paint, you take about 6 degrees off the roof in summer.