Types of flat roofs
1. Built-Up Roof (BUR)
Several layers of natural or synthetic roofing felt are alternated with hot-applied coatings of tar or asphalt in a BUR system. The top layer is often a hot asphalt layer covered with gravel. The gravel serves to reflect sunlight and protects the layers underneath.
Instead of tar and gravel, a reflective coating is sometimes placed. This smelly and dirty roofing procedure requires specialist equipment and is not a do-it-yourself affair. The more layers added, the more sturdy the roof, but also the heavier it becomes.
2. Modified Bitumen Roof (MBR)
Most modified bitumen roof systems include overlapping, single or double-ply asphalt-based sheets that are rolled out and either heat-applied or self-adhesive.
BUR was replaced with modified bitumen. There is no stinking tar here. A modified bitumen roof may also be covered with a reflective elastomeric finish to seal any cracks and reflect the sun’s beams.
This is a solution that some do-it-yourselfers can attempt. It is tear-resistant and robust like BUR, but it is more expensive, falling between BUR and single-ply membrane systems depending on the number of layers utilized.
3. Single-ply Membrane Roof
Single-ply membrane systems are the most expensive of the three kinds of flat roofs because they require flexible, waterproof sheets manufactured of synthetic materials. The following are some of the most common forms of single-ply membrane roofing:
- TPO (thermoplastic olefin)
- PVC (polyvinyl chloride)
- EPDM (ethylene propylene diene M-class rubber)
EPDM systems have been around as long as modified bitumen and have proven to be as durable. If it does get punctured, repairs are simple. It is the most commonly used material in single-ply membranes. One disadvantage is that it is dark and absorbs heat.
Advantages of Flat Roof
Roof Space
If you need a lot of room, a flat roof is your best bet. When you don’t have your own yard, you might utilize it as an outside place. Swimming pools are often installed on flat rooftops.
Simple Repairs
Flat roofs are simple to repair. Sloped roofs pose safety hazards while repairing and need the use of specialized materials to wrap around the roof’s pitch curves.
Less Materials Needed
Flat roofs may use up to half the materials that pitched roofs use. This has drawbacks, but it also means that it is significantly less expensive.
Easy to Heat and Cool
Flat roofs are simpler to keep cool and warm if your roof is well-insulated. It is very awesome! Air and heat will not be trapped in the pitch, and you may purchase a smaller HVAC unit.
Disadvantages of Flat Roof
No Attic Space
Since flat roofs do not have a pitch, they do not provide the storage capacity that an attic offers. This may be avoided by purchasing an outside storage structure, but the expense can mount up and space is limited.
Hard To Drain
Flat roofs provide little to no drainage. This need a unique drainage system or a moderately pitched roof, making genuine flat roofs practically impossible to find.
Snow and Ice Can Settle
Flat roofs enable snow and ice to accumulate. This may cause the roof to sag and, in severe circumstances, collapse. Flat roofs are not advised in cold areas because of this.