Flat Roof Materials for Waterproofing

A building or construction with a flat roof has more advantages than one with a pitched roof. However, there is a risk of leaking and repairs, which are less common in pitched roofs. However, this does not restrict the use of a flat roof.

There is no need to be concerned about leaks or repairs if proper flat roof waterproofing materials are applied. In this post, we’ve compiled a list of the most common and widely used flat roof materials that are most suited for waterproofing your roof while also providing additional benefits from weathering.

Types of Flat Roof Materials

Different types of flat roof materials which are best suited for waterproofing and weathering effects are mentioned below.

• Mud Roof
• Brick-concrete Waterproofing
• Membranes
• Tiled Finish
• Mosaic Finish
• Mastic Asphalt and Bituminous Sheets
• Flashing

Mud Roofs

Flat roofs require a finishing layer on the top of the roof substructure for the purpose of providing a water proofing layer.

In areas where rainfall is minimal, mud can be used to create a very inexpensive water-tight flat roof. Only white earth with a high percentage of sodium salt should be used for this.

Brick-concrete Waterproofing

Mud layers as a water-proofing medium are not proven to be satisfactory in areas where rainfall is heavy. Under these conditions, the optimum way is to build a layer of lime concrete made of well-graded broken bricks with a thickness ranging from 3″ to 6″ and a slope of 1 in 30 on top.

It’s best to use crude oil with a lime content of roughly 5% by weight. After the concrete is laid, it is thoroughly pounded with pointed beaters for 3 to 4 days while a thick slurry of lime and water is put on top to form a firm and continuous top layer (1″ thick) with water-proofing properties.

Membranes

The materials used for flat roofing systems in today’s modern technology are not the same as they were previously.

Some of them have been replaced with more effective and cost-efficient modern materials. Single-ply membranes are one of the materials.

There are several types of these, but EPDM is the most effective and widely used (ethylene propylene diene monomer). This is primarily made of synthetic rubber.

It is far more cost-effective and does not necessitate the use of expert labour for installation. It has a life expectancy of over 30 years. It also avoids rainfall leakage and protects the roof from the effects of weathering.

Tiled Finish

A double layer of thin flat roofing tiles is installed on the brick concrete detailed above when the terrace is intended to be used as an out-door living room or for family functions.

The first layer is laid diagonally, while the second is laid squarely. If the goal is to improve the aesthetic of the terrace flooring, hexagonal tiles could be selected instead of rectangular tiles.

Also Read : Roofing Materials for Pitched Roof
Also Read : Curved Roof : Construction, Advantages & Disadvantages
Also Read : Roof Pitch Calculator

Mosaic Finish

The above-mentioned multiple layers of roofing tiles can be substituted with a covering layer of glazed china mosaic pieces put in combination with mortar.

Any desired design might be laid by using different colors for the mosaic pieces. China mosaic tiles are strong and non-absorbent, making them an excellent water proofing material.

Mastic Asphalt and Bituminous Sheeting

A covering layer of ³/₄” to 1″ thick mastic asphalt might make an R. C. C. roof slab water proof in its most basic form. At the roof-to-parapet junction, lead flashing and concrete fillet are used.

Manufacturers provide mastic asphalt in the shape of blocks, cakes, or drums for use in construction. Heating it in iron pans liquefies it. It is combined in a 2:1 ratio with girt or broken stone when it is laid. It should be applied hot and troweled to the required thickness as soon as possible.

A layer of roofing felt and wire netting is spread before a layer of hot mastic asphalt is applied to offer water proofing in another approach.

This is important for timber floors that cannot be coated directly with hot mastic asphalt. Mastic asphalt can be coated with fine gravel or sand grit to improve its durability.

Flashing

Flashing is a term used to describe sheets of lead or other metal used to keep water out of joints. It is used when two planes of the same slope meet, as in hips, ridges, closed and open valleys; or when the vertical faces of the roof connect, as in chimney stacks, dormers, parapets, raking parapets of gable roofs, hidden eaves gutters of pitched roofs along a parapet wall, skylights, and lanterns.

The importance of these joints’ sealing cannot be overstated. To cover these joints, metal sheets made of copper, tin, zinc, or lead are used. Heavy impregnated felt or a combination of metal and felt can also be used for flashing.