Types of Roof Support Issues

Posted on: May 6th, 2017 by Lori Smith
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When you have a new home built, you get to watch the step-by-step process. However, the average person never sees the inner structure of the roof.  Honestly, most people probably don’t really care and just want the roof to provide cover and not leak.

Roof line

From Pixabay

Since this is a construction blog, though, and I’m a fan of architecture and how homes are put together, this is a topic close to my heart. The process for framing a roof really comes down to assuring it is designed to maintain the structural load, which includes its own weight, the weight of the roof covering, and any environmental load such as snow and wind.

Roofs that are well supported have a complicated system of rafters and trusses, which are the main two components of roofing systems. The following post highlights the main difference between the two:

Difference Between Rafters and Trusses | Difference Between

Roof Truss

Wikimedia Commons

Rafters and trusses are those that support the roof. Though both rafters and trusses are triangles in shape, the trusses have more triangle webs inside the principle frame. Rafters consist of sloping outer beams which provide support.

As the trusses come with a web of triangles inside the main frame, they provide more support than the rafters.

Trusses and rafters are both assembled ahead of being installed onto the roof. Trusses are assembled in a factory using pre-engineered structures and joints. On the other hand, rafters are assembled at the construction site. As trusses are assembled in a factory, a lot of time can be saved.

Read the original post here:  Difference Between Rafters and Trusses | Difference Between

If you buy an older home and want to renovate it, there are specific issues that need to be taken into consideration. Many people want to knock out walls to open up an area and make it bigger. However, you have to first decide whether the wall is weight bearing or not.

You’re best to speak with an architect first, but the man in the following video provides some good information on whether it is safe to take a sledge hammer to a wall:

Sagging walls many times originate with the horizontal ceiling rafters. To make the material span the entire area, you have to join together two rafters, which are typically lapped and toe-nailed together in the center to achieve the necessary strength. If too much weight accumulates, the joint can pull apart and the ridge line can sag.

Other reasons for problems can consist of a construction defect, a leak that is neglected, or just normal wear and tear. The next post describes the main two types of roof support issues:

Trusses

Wikimedia Commons

3 Common Roof Support Problems

1 Sagging Roof

Roof sagging is a common problem found in both old and new properties. When you look at a house from outside, the roof appears wavy and not straight. The use of incorrectly sized strutting beams or the incorrect strutting or even the absence of struts to the underpurlin can be causes of roof sagging.

2 Sagging Floor

A structural analysis will usually show that the roof-bracing system picks up most of the roof load (weight). Hence, it is very important that the roof braces land (rest) on only designated interior “load-bearing” walls. Unfortunately, many builders/framers often support the roof bracing systems on the closest or most convenient interior room partition wall. This can lead to long-term floor sagging because most floor joists are not sized for roof loads.

Sagging roof

Wikimedia Commons

Read more here:  3 Common Roof Support Problems

As mentioned before, these types of weight bearing and load problems need to be addressed by a professional. It is possible it could be a fairly simple fix with jacking up loose rafters and adding some extra strut support. However, it could also be a serious issue that could require a major overhaul, putting you and your family at risk.

 

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