Cracks keep opening: how to fill?
 

Our house is a three storey end terrace, built with brick end walls and
with concrete lintels joining the end walls. The side walls (with the
lintels) have a lot of very large windows. The remaining part is
covered with upvc weatherboarding. The house is about 40 years old, and
the lintels have sagged a bit.

Inside, on the top floor, on the side wall, a long horizontal crack has
opened up. It was there when we bought the house, and the survey said
it was nothing to worry about. Every time I fill this crack, it just
opens up again. It's only a millimetre or two wide, and it's not
getting any wider, but I think there must be a little bit of movement
there.

The interior wall is I think some kind of plasterboard attached to the
concrete lintels. The wall is just plastered and painted, there's no
wallpaper.

Can anyone suggest a way of covering over this crack more permanently?


--
Simon Elliott http://www.ctsn.co.uk

What are you using to fill the crack? Some fillers are more flexible
than others.

Bert
http://www.bertcoules.co.uk

Simon Elliott wrote:
Our house is a three storey end terrace, built with brick end walls and
with concrete lintels joining the end walls. The side walls (with the
lintels) have a lot of very large windows. The remaining part is
covered with upvc weatherboarding. The house is about 40 years old, and
the lintels have sagged a bit.

Inside, on the top floor, on the side wall, a long horizontal crack has
opened up. It was there when we bought the house, and the survey said
it was nothing to worry about. Every time I fill this crack, it just
opens up again. It's only a millimetre or two wide, and it's not
getting any wider, but I think there must be a little bit of movement
there.

The interior wall is I think some kind of plasterboard attached to the
concrete lintels. The wall is just plastered and painted, there's no
wallpaper.

Can anyone suggest a way of covering over this crack more permanently?


decorators caulk.

Simon Elliott wrote:
Our house is a three storey end terrace, built with brick end walls and
with concrete lintels joining the end walls. The side walls (with the
lintels) have a lot of very large windows. The remaining part is
covered with upvc weatherboarding. The house is about 40 years old, and
the lintels have sagged a bit.

Inside, on the top floor, on the side wall, a long horizontal crack has
opened up. It was there when we bought the house, and the survey said
it was nothing to worry about. Every time I fill this crack, it just
opens up again. It's only a millimetre or two wide, and it's not
getting any wider, but I think there must be a little bit of movement
there.

The interior wall is I think some kind of plasterboard attached to the
concrete lintels. The wall is just plastered and painted, there's no
wallpaper.

Can anyone suggest a way of covering over this crack more permanently?

Suggest exposing the brickwork and ensuring your pointing is good. And
not covering it, as you need to know if it continues to move.


NT

On 28/05/2005, Simon Elliott wrote:

Can anyone suggest a way of covering over this crack more
permanently?

Thanks for all the replies. I've bought some flexible filler from a
local DIY shop, will try to remember to post here re whether it does
the biz or not.


--
Simon Elliott http://www.ctsn.co.uk

On 29/05/2005, wrote:

Can anyone suggest a way of covering over this crack more
permanently?

Suggest exposing the brickwork and ensuring your pointing is good. And
not covering it, as you need to know if it continues to move.

There's no brickwork. That wall of the house is a series of concrete
lintels, with cladding where there aren't any windows. Whoever designed
the lintels didn't do a very good job of calculating the serviceability
limit state (I assume they had to do calcs for this in 1965?) as they
have sagged a bit.

I think the cracks opened either to the sagging of the lintels or to
settling back in the 1970s, as it seems the builders didn't do such a
good job with the foundations either. Several of the houses in the
block have had nasty settlement problems in the past. But I think the
cracks are probably moving slightly due to thermal stresses: the
concrete lintels and the stuff that was used for the cladding seem to
have very different coefficients of expansion.

--
Simon Elliott http://www.ctsn.co.uk

Simon Elliott wrote:
On 29/05/2005, wrote:

Can anyone suggest a way of covering over this crack more
permanently?

Suggest exposing the brickwork and ensuring your pointing is good. And
not covering it, as you need to know if it continues to move.

There's no brickwork. That wall of the house is a series of concrete
lintels, with cladding where there aren't any windows. Whoever designed
the lintels didn't do a very good job of calculating the serviceability
limit state (I assume they had to do calcs for this in 1965?) as they
have sagged a bit.

I think the cracks opened either to the sagging of the lintels or to
settling back in the 1970s, as it seems the builders didn't do such a
good job with the foundations either. Several of the houses in the
block have had nasty settlement problems in the past. But I think the
cracks are probably moving slightly due to thermal stresses: the
concrete lintels and the stuff that was used for the cladding seem to
have very different coefficients of expansion.


Firstly we dont know what the wall is made from, I'm assuming theres
more to it than just lintels, since they would not stay up on their
own.

Unless Im mistaken, if a concrete lintel sags, it has failed. If this
is your situation, I would not be looking to decorate over the cracks,
as it may possibly be at risk of collapse. Without the necessary info,
really we can not know what is going on, but sagging crete lintels does
not sound good.


NT

On 30 May 2005 04:22:28 -0700, wrote:



Firstly we dont know what the wall is made from, I'm assuming theres
more to it than just lintels, since they would not stay up on their
own.


1960's house then they are 13 to 14 ft wide and sit on the brick /
sinderblock walls that form the side walls.

Unless Im mistaken, if a concrete lintel sags, it has failed. If this
is your situation, I would not be looking to decorate over the cracks,
as it may possibly be at risk of collapse. Without the necessary info,
really we can not know what is going on, but sagging crete lintels does
not sound good.

Doesnt concrete take a while to fully set? They would have been cast
in situ and sagged over subsequent months. It seems very typical of
60's houses and flats and its not a major problem. If the OPs lintles
have been covered in paslter board then the house has been replastered
and the cracks are where no skrim was use. If it hasnt been
replastered but merely sounds hollow like plaster board then the sand
and cemet plaster is detatched and the fix is to replaster.

Those 13' wide windows present problems for window fitters who have
measured the reveals at the side and not noticed the sag:)











NT

mark d wrote:
On 30 May 2005 04:22:28 -0700, wrote:

Firstly we dont know what the wall is made from, I'm assuming theres
more to it than just lintels, since they would not stay up on their
own.

1960's house then they are 13 to 14 ft wide and sit on the brick /
sinderblock walls that form the side walls.

Unless Im mistaken, if a concrete lintel sags, it has failed. If this
is your situation, I would not be looking to decorate over the cracks,
as it may possibly be at risk of collapse. Without the necessary info,
really we can not know what is going on, but sagging crete lintels does
not sound good.

Doesnt concrete take a while to fully set? They would have been cast
in situ and sagged over subsequent months. It seems very typical of
60's houses and flats and its not a major problem.

Concrete takes 6 days or so to cure. If it sags even a bit, it has
sheared.

There are some situations in which broken lintels are not a significant
safety issue, but I would not at all assume thats how it is without
knowing the details. If I were the OP I'd want to find out. I dont
think we have enough info to know.


NT