Cracked Render

Absolute Beginner · Posted: Mon Oct 23, 2006 1:36 pm Post Subject: Cracked Render

My mid-terraced house dates back to 1870 and is built from concrete-like blocks whose face is around 1.5ftx1ft (I am a beginner in this sort of thing); described in our survey when we bought the property as "unusual but sound".

We now have a horizontal crack in the render and a small crack reaching down from the same "concrete" window sill on the first floor. Would I use the same render-repair methods outlined above or do I need a specialist? From having read the comments on this subject above, I am assuming that the cracks are due to water getting in from dodgy soffits, holes in the render from a new BT line being run up the front of the house and from render being cut away for the replacement windows.

I'm also assuming (and here I am being really niave) that there is no structural cause, as the horizontal crack carries along across the face of both next-door neighbours, one of whom recently bought the house with a structural survey that said no subsidence.

Any help gratefully recieved.

Thanks.

oilman · Posted: Wed Oct 25, 2006 6:09 pm Post Subject:

When was the render put on?

^woody^ · Posted: Wed Oct 25, 2006 7:35 pm Post Subject:

You can and should not rely on a survey to another property as representative of your own property.

A long horizontal crack in render is indicative of movement in the wall behind it, and the crack typically follows a mortar joint. Whether this is significant, recent or historic is another matter.

The areas around the crack should be tapped to see if there are any hollow spots. Its no good just repairing the crack if other ares need renewing too

JohnD · Posted: Wed Oct 25, 2006 7:45 pm Post Subject:

1870 in Sussex? I wonder what these blocks are? Do they appear to be stone or some kind of brick or concrete material? Are they just used on the outside faces, or on the party walls as well? Or could it be that grooves have been moulded into the render to give the appearance of stone blocks?

Is there a cellar, or is it earth under the ground floor?

Static · Posted: Thu Oct 26, 2006 8:19 am Post Subject:

Is it just 1 horizontal crack?
What height is the crack?
Whereabouts in sussex are you?

Also you say its built from unusual blocks then say its rendered, is the render a recent addition?

__________________
(Any reliance you place upon any advice given will be at your sole risk)

Absolute Beginner · Posted: Thu Oct 26, 2006 9:13 am Post Subject:

Dear all,

Thanks for this advice. It is just one horizontal crack. Yes, it is possible that the walls are a concrete-like material and shaped to look like blocks.

The material is inside and out and party walls (almost impossible to drill into as well) The horizontal crack is about level with the floor of the first floor. I'm near Horsham and it looks like the render has been replaced a number of times over the years - I have no idea when this coat was applied. There is no cellar - just earth under a gap under the floor of about 4 or 5 inches.

I've tapped the area and as far as I can tell it appears to just be the render lifting away from the wall - is this possible and could be it be caused by water getting in, especially from the replacement window frames?