Dachstuhlformen - which is there?

Not every roof truss is the same, there are very different shapes here. Which are that and some more information on the subject can be found in this post.

The different forms of trusses

The simplest form of a roof truss is the rafter roof. Here, the sloping roof beams together with the floor slab form a load-bearing triangle. The roof load is directed here directly into the outer walls.

However, this shape is only used in small buildings and for roof pitches of 35 to 60 degrees. The installation of dormers or the replacement of individual rafters are very problematic in this form.

The Kehlbalkendach has so-called Kehlbalken, which stiffen the rafters at variable height against each other. This is especially useful for larger roof structures, and also creates a possible ceiling support for the loft extension and a so-called loft.

When Kehlbalkendach but must be taken to ensure that in the contact area of ​​the rafters often concrete abutment or Rinanker may be necessary.

The third type of roof truss is the so-called purlin roof - here the rafters rest on longitudinal beams, which in turn carry the load over the floor slab with supports.

The longitudinal beams are called purlins, the columns are also called stalks. Depending on the construction method, several purlins can also be used here. In the ridge area there is always the so-called ridge purlin, on which the rafters rest.

So the most important truss forms are

  • the rafter roof
  • the Kehlbalkendach and
  • the purlin roof

Depending on the requirements, the appropriate construction method is planned in advance by the respective planner of the building and taken into account statically. This is important in order to remove the roof loads accordingly and not to overload the outer walls or the floor slab.

Tips & Tricks

Setting up a roof truss - even when rafter roof - should always get only experienced carpenters. Doing it yourself is not recommended to a home builder, even if it seems relatively easy. Do not be fooled here.

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