Lintels Rusted or Corroded – What are they
Most homeowners, probably don’t know what a lintel is, let alone that they should be maintained and not rusted or corroded.
A lintel is a beam supporting masonry above an opening in a wall, such as a window or door opening. Lintels may be made of wood, masonry or steel. Lots of homes in our area that have brick or stone walls have steel lintels.
The Brick Institute of America (BIA), steel lintels will require maintenance to avoid corrosion.
Corrosion, also known as rust when the term is applied to steel lintels, causes the lintel to expand or bloom. The expanding lintel exerts pressure on the surrounding brick or stone work, resulting in cracks and movement. I see this a lot, even in homes that are otherwise very well maintained.
That’s why maintaining steel lintels are essential in a proper maintained home.
It has become a fairly common practice to cap the lintels with aluminum and seal them with caulk. Looks good, but this practice may do more harm than good. By trapping moisture within the wall assembly, we promote rather than inhibit rust. Again we turn to the BIA for guidance. They advise that proper consideration must always be given to moisture control wherever there are openings in masonry walls. There must always be a mechanism to channel the flow of water, present in the wall, to the outside. A lack of flashing and weep holes in the original construction may limit the flow of water to the outside. Capping and caulking may make matters worse.
The BIA does not provide specifics on how to maintain steel lintels. So, what’s a responsible homeowner to do?
When I find evidence of rusty metal lintels, I generally recommend that they be cleaned, primed and painted to reduce the risk of further deterioration that could require costly repair. Use high quality paint specifically formulated for use on exterior metal surfaces. Expose any metal lintels that are capped in aluminum or are similarly concealed. Repair any damage to the surrounding masonry.
By the way, painting the lintels with the same paint used for the exterior wood trim won’t get the job done. Often the rust will bleed right through the paint.
If the lintels are allowed to continue to rust and deteriorate, they will eventually need to be replaced – a process much more costly than paint. If the lintel is sagging noticeably or if damage to the lintel or the surrounding masonry is severe or if problems recur despite maintenance efforts, the lintel may need to be replaced. In that case, the use of galvanized steel lintels and/or improved flashing techniques may serve to extend the life of the new lintel. Discuss these options with your masonry contractor.
During a professional home inspection, Central Virginia Home Inspections will inspect the readily accessible, visually observable components of the wall structure and cladding. If evidence of rusty metal lintels, it will be noted in the home inspection report.