Flat Windows and Steel Lintels

“To fit or not to fit – that is the question……” 

The question of whether or not to fit a steel lintel over a window is one that we are asked about regularly. This article gives a basic overview of the factors that we consider in each case to inform our decision. In most homes the inside course of bricks over a window will have been built with a supportive lintel in place. Unfortunately the outside course of bricks is often un-supported. If you have a take a stroll down any street in the Midlands and look closely at the brickwork above windows & doors it won’t take long before you spot a few cracks and areas of sagging brick work. The cause of this is very often that windows or doors have been replaced without giving attention to the state of the brickwork above.

We often advise customers that a lintel is necessary if we suspect that there is no lintel in place and that the brickwork above the installation is going to be compromised. The first question we are often asked in reply is “but aren’t your windows reinforced with steel anyway?” It is true that we do reinforce all our windows with steel. If you were to drill into the UPVC frame work you would see a box section of steel running throughout the UPVC. This sub-frame gives the window a solid structure and helps to guard against twisting and expansion & contraction of the UPVC throughout the seasons – as well as providing firm location points for all the locking hardware to lock into – making the window as secure as it can be. The logic for insertion of the steel is therefore less for supporting the brickwork and more for the reasons outlined above. However, it is true to say that reinforced windows are more capable of supporting brickwork than windows with no steel.

The decision as to whether or not to fit lintels is a subjective judgement which is taken by our designers and reassessed at point of survey considering each window on its own merits. The factors that would lead to the decision to fit a lintel include :

  1. the width of the window (wider windows are more likely to need one),
  2. the structure of the new window (windows with large expanses of uninterrupted glass are more likely to need one),
  3. evidence of structural cracks already present above the window,
  4. the number of courses of brickwork above the window being removed.

We find that the most common type of installation that requires the insertion of a steel lintel is directly above patio or bi-folding doors. The reason for this is that there is often a large expanse of un-supported space which is a classic recipe that can lead to brickwork problems.

If we assess an installation based on points 1-4 above and we see no reason for concern we will not advise that a lintel is required. If however, we suspect that installing a window or door without a lintel would prove to be problematic to the fabric of the building we will of course advise that a lintel is required. Please note that we do charge extra for lintel work (‘angle irons’ as we call them) at a fixed price per metre.

It is also important to remember that if a lintel is required in an upstairs room it is often necessary to conduct the work using scaffolding. It is generally not safe to attempt this type of work without scaffolding so we do build this into our quotation if necessary.

I hope this has served as a useful introduction to this issue – please do not hesitate to contact us if you require more information about this or any other double glazing related topic!