Roof Truss Rafter And Purlin
Trusses usually occur at regular intervals linked by longitudinal timbers such as purlins.
Roof truss rafter and purlin. From this shot it appears that there are three purlins on either side of the roof. The most common measurement used for rafter spacing is either 16 or 24 inches. The longitudinal horizontal beam that is sitting on a post or the principal rafter of a truss and used to support common rafters. Add to list click to add item 26 spreadweb residential roof truss 5 12 pitch 87 to your list.
A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. The purlins are the large beams perpendicular to the rafters. Note that these are normally only required to trussed rafter roofs and not for traditional purlin and rafter roof construction. Click to add item 26 spreadweb residential roof truss 5 12 pitch 87 to the compare list.
Parts of a traditional queen post roof truss. There are three types of purlins in wood construction. The boards creating the slope of the roof are wider than lumber used to build trusses 2x8s 2x10s and 2x12s are most common in rafters vs. Determining rafter s spacing is as important as setting the metal roof purlins spacing.
This is an example of a double roof with principal rafters and common rafters. You have to take the width of your roofing panel into the considerations. Rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall. The sheathing boards are sometimes called the roof deck and are painted white.
In timber construction purlins are nailed to the rafter or supporting trusses while in steel roof construction they are welded or bolted to the rafters or trusses by the means of cleats. Compare click to add item 26 spreadweb residential roof truss 5 12 pitch 87 to the compare list. Roof purlin are members used to directly support roof sheeting materials and could be made of timber or steel. Purlin plates under purlin principal purlins and common purlins.
In finished space insulation is placed between the rafter boards and drywall or other material is fastened to the face. The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge.