Steel Rafter And Purlin Roof Construction

Purlins are 2 by 4 feet and are installed much like metal roofing.

Steel rafter and purlin roof construction.

There is a chance of damaging roofing sheets if you are failed to do so. The width of metal panels will determine the rafter spacing. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. The plywood covers the entire roof and is solidly attached to the rafters providing a sturdy base for both insulation and metal roofing panels.

Purlin plates are beams which support the mid span of rafters and are supported by posts. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Purlins are installed horizontally under metal roofs. The purpose of purlins.

Let s take a look at the most common types of metal roofs for houses. First the purlins support the roof. Whether you are looking to install a metal roof on a shed or a house it s important to know the difference in the various types of metal roofs available. The use of purlins as opposed to closely spaced rafters is common in pre engineered metal building systems and both the ancient post and beam and newer pole building timber frame construction.

The metal roof purlins spacing must be done correctly within narrow tolerances. A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin. Metal building roof purlins provide three structural functions. While decking is not required for a metal roof and is often not used for shops barns or other outbuildings if a metal roof is being put onto a home or a garage the use of decking is common.

An affordable option and easier to lay than shingles tin is the most commonly used type of metal roofing. Contact fabral for additional information. They give added support to the roof and also provide a nailing surface for the end panels and drip edge. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

Secondly purlins tie the rafters together stabilizing and strengthening the structure s rigid framing. Load tables are available for all fabral panels. The wider the roofing panels the greater spacing distance you should put. By supporting the rafters they allow longer spans than the rafters alone.

For more detailed information on re roofing applications consult fabral tech nical bulletin 721 re roofing with metal. The term plate means a major horizontal supporting timber. Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. They give added support to the roof and also provide a nailing surface for the end panels and drip edge.

Do all roofing projects require purlins. Purlins should be fastened through the decking and into the rafters. Also known as sheeting rails purlins create the roofing members of the secondary framing of a steel building. This will provide a solid framework for attaching the metal panels.

Purlins are 2 by 4 feet and are installed much like metal roofing. Purlin plates in wooden construction.