#PRE FAB METAL ROOF RAFTER SPACING HOW TO#

Most span tables do not address spacing any smaller than 2’. A quick look at any span table will show that the spans given are for 2’ truss spacing. The standard spacing for residential roof trusses is 2’. What is the Standard Spacing of Roof Trusses? The other most common truss is a gable truss, which fits either end of the room and provides vertical webbing for attaching wall sheathing. If you were to look at one, it would be triangular with webbing in the shape of “W”. The most commonly used trusses in residential construction are fink – or standard – roof trusses. Going by those numbers, it stands to reason that a 32’ truss is the average size of a truss for a home in the US. That means a house that is 32×50 is average. According to The Atlantic, the average US home size is 1600 square feet. Roof trusses come in all sizes, as they are used in the garage and even shed construction.

But asking what the standard roof truss size is like asking what is the standard sized lot for a house or what is the standard size of a kitchen – it depends.

There are only standard roof sizes, and these are largely dependent on the area where you live. There is no “standard” size of the truss. It is always critical to consult with a building engineer before removing interior walls, even if you have roof trusses. Therefore if you have a home with trusses, you cannot automatically assume you can remove all your interior walls without detriment to your home. In these cases, an interior wall is needed to support the underbuilt truss. For instance, a contractor may need a truss for a 30’ span, but order trusses that are 30’ but underbuilt with a smaller dimension of lumber or just less lumber. Some contractors will order undersized trusses to save money. Whether your home has 2×4 or 2×6 framed walls, a roof truss does not need interior support provided the distance between bearing walls – the span – aligns with the span rating of the truss. Trusses are designed to bear only on outer walls.

No, roof trusses do not need support in the middle. Do Roof Trusses Need Support in the Middle? Any overhang by the top chord beyond the bottom is not considered part of a truss’ span. The span of a truss is only the length of the bottom chord. Note that the overhang of a truss is not used to calculate a truss span. A truss span chart assumes you are spanning an entire space. If that is the case, then the trusses used were likely undersized. You may still encounter homes or spaces that utilize interior spaces for trusses. Remember, the primary benefit of a truss, besides being exceptionally strong, is the ability to bridge a space without needing additional supports. As you’ll see, there are thousands, if not more, variations of trusses. A truss span table will show you spans of different types of trusses. The best way to calculate a roof truss span is to use the roof truss span table below. Since each truss is built to the specifications of a specific project, it is impossible to calculate the span yourself.

#PRE FAB METAL ROOF RAFTER SPACING HOW TO#

How to Calculate Maximum Roof Truss SpanĬalculating the roof truss span of a truss is usually not a task a typical DIYer would do themselves. While trusses over 40’ are used, they are less common as truss fabricators often have to build them first in two pieces, then fasten them after the fact. A truss is usually fabricated off-site by a third party and delivered to a worksite, where it is put in place by a crane. Trusses maximize structural engineering to provide massive strength in pieces of wood, often no larger than 2x4s. Also, trusses span much further than the other most common roof framing technique – rafters. The added interior space a truss provides in a home is highly desirable, as there are no walls or posts to impede the space.

Trusses are designed to span spaces without interior supports, and spans of up to 40’ are the most common in today’s homes. How Far Can a Roof Truss Span Without Support?Ī roof truss can span up to 80’ without support, however in any home that distance would be impractical and incredibly costly.

What is the Standard Spacing of Roof Trusses?.

Do Roof Trusses Need Support in the Middle?.

How to Calculate Maximum Roof Truss Span.

How Far Can a Roof Truss Span Without Support?.

Pre fab metal roof rafter spacing