Lintel blown? resin filler

anna.bloom

We are in the process of having our wall ties replaced and old ones isolated.
We had two quotes, one for £1600 and one for £1434. We went for the cheapest

We have a big crack down the side of the house above the kitchen window. And the lintel could be blown, nobody can tell until they cut it out and take the external render off.

However the wall tie man who has done our wall ties, said to me originally he could do something that would secure it for another 20 years. Now he is denying that? and is just willing to fill the crack in.

The other company who were charging £1600 were going to fill it with a resin filler, i wish i had gone with them now.

I am very confused. If there is steel in the lintel which has rusted, surely it needs addressing?

anna.bloom

I have just spoken to our wall tie man again, and he said a resin filler would nto work, you need to replace the lintel.

That would cost us hunderds no doubt. Dont know what to do?!

casper_g

Have you spoken to your insurer?

ormus

replace the lintel. do not repair it.
lintel are very cheap to buy.
they start from 10 quid for small ones. i doubt yours will be more than 100 quid.

ormus

forget insurance. its wear and tear. not storm damage.
and you dont want them looking into any possible subsidence problem!

iamcornholio

Concrete lintels will happily stay in place even if cracked.

The main problem is not a structural issue, but rather water penetration to the crack, causing the reinforcement to rust which will initially stain the render, and then potentially cause some spalling of the lintel and render as the steel rusts and expands.

Replacement is not always necessary, but each case is different - exposure to prevailing weather can determine how soon things happen, and it could take years or decades for deteriation to occur

Resin fill may be OK to prevent moisture ingress, but it will then rely on the render keeping most of the water out of the wall behind.

But ultimately, if the area can't be treated to prevent moisture getting to the reinforcement, then replacement is the only long term option. So you need to decide if the work is worth doing now, or waiting to see how things develop.

Concrete lintels, and walls do crack - it's not unexpected or uncommon. So unless there are other signs of structural movement to that elevation, then you can deal with as above. If this crack is connected to other ongoing movement (which your surveyor for this repair should have identified) then the cause of that movement should be diagnosed and rectified

Presumably, the contractors are installing some "heli-bar" reinforcement across the wall crack proior to re-rendering?

anna.bloom

Hi there

Thanks so much for the comprehensive replies. No plans for heli bar i dont think. I have just taken a look at it on screw fix, looks like long wire.

I could ask the guy to fit it i suppose? i wondered how it works?

Thank you!

iamcornholio

The thing is, if you have had a contractor/surveyor survey for the purpose of tie replacement, then I would expect some comment on existing cracks, and some sort of recommendation as to how to deal with them.

i.e. its no good just replacing wall ties if there are other [structural] issues going on.

This is not saying that the crack is a significant structural issue, or that you should be unduly worried about it. But the crack may have relevance to the tie replacement work - in which case the surveyor/contractor is obligated to at lease consider the existance of the crack and any possible implactions to the work being done. Or to advise you to get the crack looked at professionally for more considered opinion

The reason for the crack needs to be established, and then suitable remedial work devised.

So basically, I would expect these people to have told you that the crack was/was not an issue and included for a suitable repair of the crack and render. And a suitable reapir would normally entail these heli-bars to prevent the render re-cracking after repair

Dry_Rot

The thing is that you need to know what the lintel is composed of. Is it a concrete lintel with re-enforcement inside - or a steel lintel with render on top? Is the crack vertical or is it running horizontally. It could be nothing to worry about, especially if it is confined to the face of the lintel and is not extending into the brickwork above. If the lintel is concrete and the cracks run horizontally, then the re-enforcement is rusting and the expansion of the metal is pushing the face off. In this case. localised repair would only be worth while if the lintel was very deep or the opening very wide. If it is not such a big lintel, replacement is cheaper and longer lasting.

Metal lintels which are rendered over with sand/cement will crack eventually anyway. Some corrosion of the lintel is inevitable and this, combined with differential movement between the steel and render will show as cracks. In this case widen the crack and fill with a faily soft cement pointing - resin is not good here because it is vapour proof and whilst water can get in through adjacent porous render - it will not evaporate out of the resin filled bit - so eventally the damp would become worse. Resin is also much harder than cement, so it will re-crack at the resin/cement interface as expansion and contraction happens.
Hope this helps.

littlesnuggy

Look at the helifix website for info on helical rods - they effectively reengineer your existing brickwork into a beam.

anna.bloom

Hi its concrete, and now the wall tie man has exposed the render he says it has not blown. He says the horiziontal crack has been caused by ash, which soaks up lots of water. He has put a scratch sand and cement render quote on, and will finish it off tommorow hopefully making it waterproof.

On another note, he is filling the isolated wall tie holes with render, but the small holes where he has fitted new wall ties, with decorators caulk. Is this right?