The Pour and Roll Systems. (Built By Felt)

The roll and pour system has been in the market place for many years, and is still widely used in industrial and domestic instances. There are many types of roofing felts available ie Rag Fibre, Fibre Glass Reinforced and the Elastomerics, it  would be wise  were ever possible to use the Elastomeric systems when ever possible as these are the systems that will give you a life span of approx 15 years plus. See outline below:

Bituminous flat-roof coverings

Bituminous flat-roof coverings also known as roofing felts or membranes are designed to be fixed on to the surface decking of flat roofs to protect them from the elements. They are supplied in a wide variety and combinations of materials with effective lives that range from less than 5, to over 20 years. They are estimated to constitute about four-fifths, by volume, of the non-metal flat-roof coverings sold in this country.

Although there is a wide diversity in the quality of materials and methods of installation, most bituminous felts are designed to be applied to roofs in a number of layers usually two or three as part of a roofing system.

The make-up of such systems can vary widely. Some involve a base sheet, an underlay and a covering cap sheet, all made of the same types of material. Others use specialized felts that can be applied only as base sheets or underlays, while others still involve a mixture of different types of felts, with cheaper materials being used for base sheets and underlays and more advanced products as cap sheets.

Systems that use the more advanced types of felts, and which are laid by approved contractors whose staff may have been specially trained, are often backed by manufacturers’ guarantees; the others are not.

Felts are manufactured by immersing a roll of core material in bitumen and then coating it with oxidized or modified bitumen. In most cases the top side is also given a surface covering such as sand or slate granules and sometimes the underside is treated with an adhesive. The most traditional and lowest quality of the core materials to which bituminous coatings are applied is an absorbent fibre sheet, known in the industry as ‘rag’. Although this is cheap to produce, it is prone to tearing when being applied to roofs, and rots over time. Its poor quality makes it suitable only for low-level applications such as garden sheds, or as the bottom layer in a built-up roofing system where the other layers contain higher-quality materials. But, because it is so cheap, it continues to be used as the sole covering on the roofs of some garages and domestic extensions.

The first higher-quality core material to appear was glass fibre sheeting, which was introduced in the 1950s. This is more resistant to tearing during application, and does not rot. It is suitable for a wider range of applications and, unlike rag-based felts, is used on commercial and industrial as well as domestic buildings.

The highest-quality core material is polyester which first began to appear in the 1970s. This is very resistant to tearing, does not rot and can be used for all types of flat roofs. The bitumen coatings for these materials are divided into three broad groups. The traditional one is oxidized bitumen which is the cheapest to produce, but lacks flexibility particularly at lower temperatures, has little capacity to cope with any movement in a roof and can become brittle and crack after exposure to sunlight. The other two coatings are achieved by mixing bitumen with a modifier which leads to felts which can be easier to apply, are harder wearing, and have a longer life and improved performance. Bitumen mixed with atactic polypropylene (APP) or the rubber-like styrenebutadiene-styrene (SBS) is particularly suitable for ‘torch on’ applications (see below) and is more flexible in low temperatures. Felts coated in SBS bitumen are more expensive than those which use APP, but are better able to accommodate movement in a roof without cracking.

There is also a range of ways in which felts can be applied to a roof. The most traditional method is known as ‘pour and roll’. This involves heating bitumen to a high temperature and pouring it on to the surface of a flat roof. The felts are then rolled on to the hot bitumen, forming a bond with the roof as the bitumen cools and solidifies. This method normally requires a team of three or four men.

Should you require a built up felt system a full in depth survey can be carried out, on completion a detailed specification detailing the type of materials to be used and our recommendations  along with the guarantee periods available will be submitted, a full quotation will be attached to the specification for your approval, with all high performance systems there are still options available from all the main manufactures which carry a full 10 year insurance backed  guarantee.

All systems can be installed : Warm, Cold, Inverted, Ballast, Balconies with walkway tiles, Green Roofs.

Our Technical staff are on hand to assist clients with technical assistance on all  matters concerning our range of  flat roofing services, whether it be problem solving, specifications or general enquiries.

We offer a full nationwide service for all our clients.   

FIRST CLASS ROOFING SYSTEMS UK are also in the unique position to have our own in house Cad design / Technical department, this enables us to supply detailed drawings for all your requirements.

We are approved installers for many roofing in all instances the products supplied and installed by our company will carry a  full manufactures guarantee and will be installed by approved and fully trained operatives only.