The Complete Guide To Types of Flat Roofs in Kenya

A flat roof in kenya refers to a rooftop that is almost horizontal with only a slight slope of 10 degrees to drain away the water when fitted properly. This roof can be constructed in a variety of ways with the most prevalent being sloping and standing seam roofing. Let’s take a look at the complete guide to types of flat roofs in Kenya.

built up flat roof in kenya


Types of flat roofs in kenya 

Based on the materials used there are different types of flat roofs in Kenya each of which has its own advantages and disadvantages, they include:

  1. Built up roof
  2. Modified bitumen roof
  3. Membrane( single-ply )roof


  • Built-up flat roof

Before the advent of modified bitumen and membrane roofing systems, built-up roof (BUR)membranes were used as the flat roof material of choice. This material consists of several layers which include; a bottom layer of insulation board, several middle layers of bitumen alternating with reinforced fabric layers(ply sheets), and a top layer of gravel. asphalt, coal tar, or cold-applied adhesive is the bitumen that is mostly used in built-up roof systems. the hot applied tar mixes with the bitumen-saturated reinforcing fabric to create a monolithic roof membrane.

Pros of a built-up roof

  • Cost-effective

    – It is the cheapest of all flat roof varieties

  • Removable layers

    – The layers can be removed when repairing the roof

  • Fire resistance

    – It offers excellent protection  against fire

  • Easy to maintain –

    It costs little to maintain throughout its life cycle

Cons of a built-up roof 

  • Difficult to install

    – It is very heavy and requires reinforcement of the roof deck before installation

  • Not environmentally friendly

    – It emits dangerous fumes during installation

  • Labor intensive

    – installation of the built-up roof is labor intensive and it is difficult to identify and fix leaks 

  • Prone to damage

    – this roof is not flexible during cold weather and therefore prone to damage.


modified bitumen flat roof


  • Modified bitumen flat roof 

Modified bitumen roofing(MBR) is an asphalt sheet roofing that was developed as a lighter alternative to the built-up roof. it is for buildings with low slope structures and designed using the built-up roofing technology with the addition of polymer reinforced roof wears or rolled sheets. modified bitumen may be fitted using the torch application method while other versions come with a self-adhering sheet

Pros of modified bitumen

  • Ease of installation

    – it is easier to install compared to a built-up roof

  • Environmentally friendly

    – it is free from volatile organic chemicals during and after application and can also be recycled.

  • Ease of maintenance

    – it is durable and low maintenance and offers flexibility at low temperatures.


Cons of modified bitumen

  • Least attractive

    – it is the least attractive of all flat roof varieties

  • Dangerous application

    -When done by a non-professional the torch application method can cause fire 

  • Prone to damages –

    it is prone to tears and the overlapping joints can cause leakages when not properly adhered.


  • Membrane (single-ply) flat roof 

This is the latest flat roofing technology and material of choice for homeowners. as the name suggests single-ply flat roofs are designed to be installed in a single layer and are categorized into two; thermoplastics and thermosets. thermoplastic membranes are designed to include a reinforcement layer, normally polyester or fiberglass to offer supplementary strength and stability.

Thermoset membranes on the other hand are made from synthetic rubber polymers, with ethylene propylene diene monomer (EPDM) being the most common. both thermoplastics and thermosets are very flexible and resistant to UV radiation.

Pros of single ply

  • Lightweight –

    it is lightweight and does not require reinforcement of the roof deck

  • Resistant to damage

    -this material is highly resistant to scuffs ad tears 

  • Does not leak

    – this roof does not leak easily unless surface damage occurs and the leaks are easily repaired. 

Cons of single ply

  • Expensive

    – this is the most expensive of all flat roof varieties.

  • Prone to  punctures

    – this roof is easily punctured by food traffic  leading to leaks 

  • Difficult installation

    – chimneys and roof penetrations make installation difficult.


membrane (single ply) flat roof in kenya

Wrap up

As the demand for outdoor entertainment continues to rise homeowners are erecting concrete roofs instead of the above roofing systems and fitting them with tiles to create open-air living areas. Tiles for flat roofs must be UV resistant and waterproof. However, if you do not intend on using the rooftop space then consider one of the above types of flat roofs in Kenya. 

99 Construction Guide
99 Construction Guide

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