They find a new crack in the walls of their house?

I have noticed a couple of new cracks appearing about 1mm wide in the walls of our house. These are internal in the plasterwork and are crazed in pattern (i.e. Not following the course of mortar or bricks). The house is a 1970s detached.

Some appeared at a similar time last year too and I put it down to a dry spring/summer but two years running is a little worrying. Last years cracks are very slightly wider than they were 6 months ago. I know polyfilla has its purposes but should I be a little more concerned about the new cracks developing? Or is it just that in the 70s houses weren’t being built all that substantially? I have noticed cracks in other houses around too (same housebuilder and underlying geology) but ours seem a little worse. Most of the cracks are around windows, either at corners or in the middle under the cill, but a couple are in the corner of the rooms. The boundary of our garden is made up of 4m high confirs about 5m away from house, could this be an issue?

Not an expert- but a worrier!

I don’t think that you need to be too worried by these. The way you describe them, it sounds like they are just in the plaster and not in the structural material (bricks, mortar, etc.)- could well be a seasonal thing.
Maybe check that you have sufficient airflow through the house?

If it was movement in the house, surely the cracks would be in directional lines?

Keep those conifers in check though!

as above its probably just the plaster cracking. only worry if they are getting wider all the time. glue some glass across the crack with apoxy resin. if the glass breaks the cracks are widening in which case you should probably get a professional to come and have a look as it could be

If you have a matching crack on the outside or you can stick your hand in it then I’d worry. A few small cracks in the plaster is not an issue at all IMHO

Where are you and what is the local geology? Our house is on clay and we get cracks opening in dry weather that then close when it rains hard enough. The house is just over 100 years old and hasn’t fallen down yet…

You only need to worry when the cracks come from the ground.

house built in the 70’s? That’ll be the crappy carlite bowning blowing from the brickwork.

It just doesn’t bond properly an comes of in huge sheets. Be very careful when you decorate!

Unfortunately, it’s days are numbered and it will only get worse over time. It won’t fall of tomorrow, but will continue to crack everywhere for a good few years yet. A re-skim won’t help either and would be a waste of money, the whole lot needs to come off eventually, right back to brick.

Just persevere with pollyfiller and decorators caulk…..

This is normal right?

we get the same in our 80’s detached house – we are on a clay based ground

scaredypants, the house is in nottingham so reckon there will be a fews years before it falls into the sea!

underlying geology is bunster sandstone (part of the mercia mudstone group) according to local maps. it’s quite clay-ey from experience of digging in the garden.

funkymonkey – i’ve never heard of carlite browning before. there are a whole load of hairline cracks all over the walls which I had previously thought were the plaster ‘drying out’ and would just need reskimming. would this carlite stuff cause cracks to appear at the corners of windows and doors etc?

I have some bricks on the outside of my house that have cracked, a few are in a line diagonally up the wall, I was worried until I looked and every house in the road has them in the same place where a wall goes between the 2 houses guess it stresses the bricks a little so am going to get a quote to replace the cracked ones, any idea how much I should pay for say 10 bricks to be replaced?

Are they originating from a plasterboard ceiling? The big old sheets can sometimes move a bit and take the wall plaster with them.

i have a edwardian house on clay, as above i get seasonal crack that open up when the clay dries out and close again when the clay soaks up rainwater, i wouldn’t worry at all, as previously said, you should only worry about a crack that big enough to get something inside it 🙂

As above regarding clay, if the crack is cyclic and can be counted in single digit mm, then there is nothing to worry about. It is simply the natural clay heave associated with wet and dry weather.
One question though, do you have any trees nearby and if so, what species and how far from the building?

Just temperature differences between inside/outside skin of the house, and maybe humidity levels causing this??

That’s what I’ve pinned it down to in my last (lates 60’s flat) and current house (70’s)

They appear pretty much in the ‘coolest’ point of the house or the points that take the brunt of the weather changes.

kevj – there are trees – some conifers form the boundary of our plot instead of a fence. they are 4m tall and the closest is about 2m from the house, the majority are about 5-6m from the house.

we did put in a decking at the back last year before the first cracks appeared and the decking it fixed to the house below dpc – is it possible that the house is just settling under the additional loading from the decking? it is about 30sq m of decking so quite a large area and its hung from the house.

how do you mean hung from the house? I take it that there is supports to the ground too?

Our decking hangs from the house – dirty great bolts into the bricks / boundary wall to all sides – it doesn’t touch the floor at all.

big frame fixers to the house on one side and then post in the ground on the edge away from the house.

swoosh

kevj – there are trees – some conifers form the boundary of our plot instead of a fence. they are 4m tall and the closest is about 2m from the house, the majority are about 5-6m from the house.

I would almost certainly cancel out tree influence. If they had been mature deciduous trees, then they can have an affect on clays local to foundations as they draw water, particularly during dry spells (Of which we have certainly not had)

It maybe roots, but again, 4m conifers will not had a significant root system, at least, not one which will affect the foundations.

If you are concerned, buy yourself a Tell-Tale and record the crack over a period of months to see if it is propagating. Note, the second reading may show significant change, use this as the datum and refer any changes to this only, not at the point of installation.

I remember when a water main burst in Nottingham and nobody realised until the water started running out. All the water had disappeared into a giant hole in the ground so they had no idea where the burst was. Lots of holes in the sandstone.

Mines too probably…