A roof’s waterproofing membrane must be durable, elastic, tear-resistant, and robust to stretch to fill cracks and move with the structure. The membrane should be UV stable if exposed to the sun. The membrane should have the flexibility to conform to any shape it is placed over and be able to turn up and over other building elements, such as walls.
Therefore, choosing the appropriate waterproofing membrane is crucial. It is possible to lay a waterproofing membrane underneath the last tiles and over the structural slab. By doing this, it will be prevented water would leak into the structural slab.
Overview of membrane roofs
Membrane roofing is one type of roofing technique for buildings and tanks. It offers a single-layer waterproof roof covering to safeguard a building’s interior. Membrane roofs are most typically used in commercial settings, despite becoming more and more popular in residential ones.
The ideal option for your roof is membrane roofing if it is flat or has a slight slope. At JP Franklin, membrane-based roofs are installed, maintained, and replaced.
Waterproofness of breathable roofing membrane
The nature of the breathable membrane makes it exceptionally waterproof and resistant to snow and dust. If properly installed, it will shield against wind-driven rain or snow and keep it from leaking between roof tiles.
A BBA-approved low resistance (LR) breathable roofing membrane allows moisture to enter the batten space above. Any stored moisture must be able to evaporate. Therefore, there needs to be ample airflow. For design purposes, WRAPTOR has a vapor resistance of less than 0.25MNs/g.
Materials and varieties for membrane roofs
There are many kinds of membrane roofs, so it’s important to talk with your roofing contractor to figure out exactly which material they want to use. The main types of membrane roofs on the market today are glass-reinforced plastic (GRP), liquid “paint-on” roofing, modified bitumen, thermoset (EPDM), and thermoplastic (PVC or similar material).
With the most recent technological breakthroughs, EPDM has transformed the flat roofing business and is possibly the most widely used Membrane roof today. Ethylene and propylene are two primary components obtained from oil and natural gas.
Different types of roof waterproofing membranes
1. Modified bituminous roof membrane that adheres to itself
Self-adhesive modified bituminous membranes are frequently stored in cardboard boxes or wrapped in opaque material. Unprotected self-adhesive goods shouldn’t be kept in direct sunlight since UV radiation might change the adhesive’s characteristics, especially on the roll’s outer convolutions, or cause the roll to “dog-leg.”
The roll alignment or the adhesion characteristics of the self-adhesive bitumen might be affected by storage for long periods or in harsh environments. Self-adhesive modified bituminous membranes, which may also contain mineral stabilizers, are made of asphalt, polymers, and tackifiers.
2. Bitumen membrane for roofs treated with polymers
The bitumen sheet membrane’s polymer modification increases flow resistance, allowing the material to be used in scorching climates. A polymer film with unique graphic features that melts when appropriately heated is placed over the material’s bottom side.
The material has a polymer layer covering it on the upper side. Modern products are made to be installed on buildings and constructions as the bottom layer of a double-layer roofing system, waterproofing the foundations, and technical systems. On pitched roofs, it can serve as an underlay for bitumen shingles. They were used for renovation or new construction.
3. Liquid Or Paint-On Roofs
By applying a specialized liquid roof coating, liquid roofing serves to waterproof a roof. It works well with various shapes and sizes of flat, pitched, and domed roofs. Liquid roofing covers a roof with a liquid-based, monolithic covering that is completely bonded.
The coating hardens to create an elastic waterproof barrier that resembles rubber and can be stretched without breaking. Such coating systems are frequently strengthened with additional components, such as glass-reinforced plastic, to provide greater tensile strength. Most conventional roofing materials may be covered with coatings, including felt, asphalt, bitumen, and concrete
4. EPDM membrane for roof
Bonding adhesives are used to install EPDM membranes. Fast and, most importantly, safe installation. Today’s materials come in the form of single-component cementitious, polymer-modified, non-reactive, selective fiber-reinforced repair mortars, which have excellent properties and are resistant to corrosion, carbonation, and shrinkage cracking. It may be applied using a hand trowel or a specialized mortar sprayer.
How much time will it last?
Breathable roofing membranes can last a lifetime, according to the product and manufacturer’s guidelines. If you need to replace your roofing membrane, the price can range from £2,000 to £7300+ (the labor to remove and replace the roof tiles accounts for most of this expense) (checkatrade.com).
A leak at the site of a ruptured membrane is frequently the first indication of a damaged roof. A patch repair may sometimes be far less expensive than completely replacing the membrane. Therefore it is a good idea to see an expert if you think there may be a problem.
What membrane thicknesses are available?
The thickness of the roofing membrane can be found in a range of GSM measurements. “Grams Per Square Meter” is what this term means. The more significant number frequently indicates the physical thickness of the material. Roofing membranes with a higher GSM rating are employed where there are stronger winds.
Typical problems with membrane roofs
- A problem with rubber membrane roofs is water ponding and leakage. These are brought on by subpar design, installation, and upkeep. You must thoroughly consider your roofing business options and confirm their level of expertise and training.
- Punctures are another problem with rubber membranes. Tradespeople walking on the roof can harm the underlying substrate and produce scratches or cuts in the membrane. Adding walking routes or more sacrificial membrane layers is one way to solve this problem.
- Modified bitumen membranes or older EPDM roofs may shrink due to material aging, inadequate installation, and UV exposure. The primary issue is that it may pull on flashings, causing splits and fissures that permit moisture to enter.
- Shrinkage issues plagued unreinforced rubber roof systems a few decades ago, but they are now less severe owing to technological developments and improvements to EPDM roofing.