Common Structural Mistakes in DIY Projects (and how to avoid them)
Updated: Sep 22
With the rise of home renovation shows and online tutorials, more homeowners are taking on DIY projects themselves. While decorating, tiling and other cosmetic improvements can be great DIY projects, changes involving the structure of your home require more careful planning.
Structural alterations can affect how loads are transferred through a building, and seemingly simple changes can have implications for floors, walls, roofs and foundations.
At Pavol Zajac Structural Engineers Ltd, we provide structural design, drawings and calculations for planned residential building projects. Involving a structural engineer at the design stage can help ensure structural alterations are properly designed before construction begins.
1. Removing a Load-Bearing Wall Without Structural Design
Creating an open-plan kitchen or living area is a popular home improvement, but removing an internal wall isn't always straightforward.
Why it's a problem
Load-bearing walls transfer loads from the floors, roof or walls above into the structure below. If a load-bearing wall is removed, an appropriate structural solution is normally required to safely support those loads.
How to avoid it
Speak to a structural engineer before removing the wall.
We can determine the loads involved and design the appropriate structural support, which may include an RSJ or other steelwork.
Structural drawings and calculations can then provide your builder and Building Control with the information needed for the proposed work.
2. Using the Wrong RSJ or Steel Beam
Steel beams are commonly used when creating larger openings in residential properties, particularly when removing load-bearing walls or building extensions.
However, choosing a beam isn't simply a matter of selecting a standard size.
Why it's a problem
Every project is different. The size and specification of a steel beam depend on factors including the span, loads being supported, bearing arrangements and the surrounding structure.
Using an unsuitable beam or support arrangement can result in excessive deflection, inadequate support or difficulties with Building Regulations approval.
How to avoid it
Have the steelwork professionally designed for your particular project.
We provide structural calculations, drawings and specifications for beams, columns, padstones and other supporting structural elements.
3. Getting Foundation Design Wrong
Foundations are one of the most important parts of any extension, new build or other substantial building project.
They transfer the weight of the structure safely into the ground and need to be appropriate for both the proposed building and the site.
Why it's a problem
An unsuitable foundation design can affect the performance of the structure above and potentially create expensive construction problems.
Foundation requirements can vary depending on the proposed structure, ground conditions, nearby trees and other site-specific factors.
How to avoid it
Consider foundation requirements as part of the structural design process rather than leaving them until construction begins.
Where required, we can provide foundation design and structural calculations as part of the wider structural engineering work for your project.
4. Adding Too Much Load to Floors and Roofs
Projects such as loft conversions can significantly change the loads carried by an existing structure.
Existing ceiling joists, rafters and other structural elements may not have been designed for the loads associated with the proposed use.
Why it's a problem
Adding loads without appropriate structural design can result in excessive deflection or inadequate structural support.
How to avoid it
Plan the structural requirements before construction begins.
A structural engineer can calculate the proposed loads and design any additional beams, joists or other structural elements required to support the new layout.
5. Removing Important Roof Structure During a Loft Conversion
Creating usable space within a roof often involves significant changes to the existing structure.
Existing timbers or bracing should not simply be removed to create additional space without considering how the proposed loft conversion will be supported.
Why it's a problem
Elements within the existing roof may form an important part of its structural system.
Changing or removing them without an appropriate replacement design can affect the way loads are transferred through the roof and into the building below.
How to avoid it
Have the structural elements of the loft conversion designed before construction begins.
Depending on the project, the structural design may include new floor joists, steel beams, trimming around stair openings and alterations to the roof structure.
Plan Structural Alterations Before You Build
DIY can be a great way to improve your home, but structural alterations are one area where good design at the beginning of a project can prevent problems later.
If you're planning a house extension, loft conversion, load-bearing wall removal, structural alteration, foundation or new-build home, Pavol Zajac Structural Engineers Ltd can provide the structural design, drawings and calculations needed to help move your project towards construction.
Planning a Residential Building Project?
Tell us about your proposed building work and, where available, send us your architectural drawings.
Contact us today to discuss your plans.
