Repairing, reinforcing crack in corner of walls

By Andy the stuff doer

This was, hopefully, nearly the very last bit a structural reinforcement required.  The front stone wall, even though it is 2 foot thick has bulged slightly outwards over time. A gap / crack had opened up between the outer wall between the window reveal and opening to passage way and the single skin brick wall of the passageway.   This section of the outer wall between the the window and passage way is a column just 1 foot wide and as you can see it’s not in the best of condition with missing mud mortar and brick being added on so it’s no surprise the deflection had occurred.

I wasn’t too concerned about the crack as I could tell it had been filled a number of times over , quite possibly, a few hundred years. However the cement render on the passageway side had cracked indicating it was still moving during the last 50 years. So it did need some attention more than just deep pointing up the stone and refilling especially as there is nothing tying the walls together.

stone wall crack in corner

Crack and gap between stone and brick walls reinforced with steel bars

The bricks where just butted up to the wall, and the stone wall had some wide gaps in it where the mud mortar had disappeared.  The solution for brick structures with reasonable mortar would be to helical stainless steel reinforcement, on “off the shelf” solution.  In this situation I could fit cheap, heavy duty galvanised steel straps.

The top one could be screwed to the timber beam and the bottom one screed to a lateral timber built in to the wall.  The middle two are set in mortar joints.

Steel bar wall reinforcement

Galvanised steel bar inserted in to stonework and screwed to beam

The more interesting ends are where they go in to the stone wall.

steel bar stone wall crack repair

Steel bar for reinforcement with screws as pins to resist pull out.

The steel bar come pre drilled with many convenient holes. To resist the bar pulling out of the stone wall I put stainless steel srcews through that would pin the bar in when the cavities are re-mortared. As they are a loose fit and can jiggle about they do allow the bars to be positioned just in the right place without having to adjust and chip away at the holes they fit in.

With the bars fitted the holes, cavities and joints in stone wall where packed with grit sand and NHL mortar with extra pinnings (stone chips) where required.   This may have stopped any future movement in it’s self but the belt and braces approach ensures the best chance completely curing the cracking corner problem.  And if that isn’t enough the crack its self was filled and reinforced with mesh.

mesh reinforcement in corner of walls

crack in corner repaired with extra reinforcement with mesh

I fished it off be pointing the brickwork and rendering the stone with a soft sand mix. The stone wall rendering is done to follow the contour of wall as once painted it should be a fairly close match to the wall at the other side of the window.

2 Responses to “Repairing, reinforcing crack in corner of walls”

  1. Andy, did you have any damp issues? I am looking at a 150 y old stone cottage now which has its back wall at the road height, I mean the road is straight off it. The stones and dirt are straight onto the wall. There is constant moisture there. Also, the main part of the cottage is on the ground, no insulation whatsoever :)
    Have you dealt with such a thing?
    Thanks
    Margarita

  2. Sorry for the late reply, I’mm having spam problems.

    Yes I’ve dealt with many damp issues, enough to know that it’s impossible to suggest a general cure. Please explore all the potential causes and don’t be taken in by the first person who suggests tanking and waterproof cement. First tackle any obvious things, constant splashing from the road could be alleviated by good lime pointing and or a breathable coating paint or silicate treatment. Make sure water runs away from the base of the wall. Internally the walls will be better off breathing than being sealed.

    What to do with the floor depends on the construction, how damp it is and how much building works you want to go through. Carpets and or rugs can make a big difference. If you want a really well insulated house then you probably don’t want an old stone cottage, no doubt it can be improved but wait a while to see how much of a problem it is first then you can weigh up the options and costs.

    All the best with it
    Andy

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