Expanding lintel? Any builders out there?

[linusberry]

We have a horizontal crack in the mortar and brickwork across the top of our upstairs windows. It has been suggested that the original steel lintels (house was built 1962) may be rusting in-place, effectively getting thicker, causing upward pressure on the bricks above them. Does this sound plausible/common, and if so, what is the rectification please?

[The Builder]

This is a tough one linus.......... without looking at it.
I would doubt if they were steel lintels in 1962. More likely concrete with steel reinforcement. It is possible for steel to rust and "blow". Alternatively, it also possible that the roof has lifted during rough weather. In those days, roof structures weren't tied down the way they are now.
How many windows, and roughly the width? (1200mm/4')?

[marden40]

I doubt, to be honest that its anything to do with rusting of the lintels, as the builder says, above windows in those days were constructed differently to how they are now....... there is normally very little brickwork between the window and the roof making this a weaker area and movement is quite common, as you have various materials together reacting to weather conditions slightly differently such as wood/plastic windows, metal and concrete lintels along with the wooden roof structure, all working around a few courses of bricks.

[joesdaddy]

Hi i have changed quite a few steel lintels which like you say have rusted and distorted the courses above, they some times used a steel single skin lintel with brickwork built in it and a cavity tray above I replace them with modern single leaf catnic lintels .Most of the houses which I have changed them where about 60 s 70s

[linusberry]

Thanks for the answers guys. Buildersmate - the house is a slightly unconventional design. We are talking about three separate windows, two of which are about 1000mm wide, and one is c.2000mm. The crack runs across the top of all three. Marden40 - the unusual design means there is loads of brickwork above the windows (the front face of our house looks like a gable end). Joesdaddy - many thanks - your explanation is practically the same as the guy who's looked at it. Cheers to all.

[linusberry]

Whoops. Ever so sorry The Builder, got your name wrong there. Please excuse the typo.