The Danger of missing lintels

Antill & Co. Chartered Surveyors carried out a RICS Home Survey Level 2 (RICS HomeBuyer Report) on behalf of a client purchasing a three-bedroom semi-detached late 1940s house located in Rowland’s Castle, Hampshire PO9.

The survey highlighted several defects, one of which was the absence of lintels above the windows of the property.

The original window frames would have been constructed of timber and have since been replaced with uPVC double glazed windows. The original timber window frames would have provided support to the brickwork of the outer leaf/skin of the cavity wall construction. The inner leaf/skin of the wall is supported by concrete lintels.

Since removal of the original timber frames the brickwork above the window openings is no longer adequately supported and this has resulted in structural movement, evidenced here by the dropping of the brickwork above the window, as shown in the photograph below.

There is now a gap between the uPVC window frame and the brickwork above it. The bricks have dropped into this gap. The uPVC window frames in this case are not designed to carry load, such as brickwork above the window. This may cause the uPVC frame to fail, in the form of:

  • distortion of the frame resulting in difficulty opening / closing the window due to the weight of brickwork bending the frame
  • the double glazing sealed units breaking, resulting in broken or cracked glass and/or the sealed units failing, most probably resulting in condensation forming on the internal glass surfaces.

To prevent ongoing structural movement above this window the issue now requires rectifying. The repair involves careful removal of the bricks above the window frame and the insertion of a steel lintel. The bricks can be put back into position and made good. Additionally, there were no cavity trays above the windows. Cavity trays are fitted above window openings to prevent moisture penetrating from the outer leaf of brickwork above the opening to the inner leaf. Consideration should be given for insertion of a tray whilst the lintel works are being carried out, to minimise the risk of rainwater penetration into the property.

In this case, there were seven windows affected by lack of adequate lintel support above the window openings. The cost of rectification is estimated at £500 per window, equating to £3,500 in total.

The RICS Home Survey Level 2 highlighted £3,500 of remedial costs on this issue alone that our client would have otherwise been unaware of prior to purchase. This valuable insight provided our client with the opportunity to revise the purchase price of the property prior to exchange of contracts and avoided the discovery of costly issues after moving in. Forewarned is certainly forearmed.