Covering up cracks in internal walls

hello,

you have solid brick walls

they then render (sand & cement) to level and then apply a hard set plaster (smooth finish)

the cracks are through the hard plaster and render, and generally due to movement of the brickwall which has moved because of foundation issues etc

most likely the cracks would be over/around the mortar lines of the brickwork as this is the weakest part of masonry wall

if cracks are through bricks you are more likely to get reasonably straight vertical cracks

thankyou
myla

Thanks myla the lingo you all use makes sense now.

Yes, on the external walls, the cracks seen are through mortar lines

GSJ

Hi,

Having just re-read this thread the two options which stand out for me are:

1. New plasterboard sheeting over the top (with removal/replacement of architraves/cornices/skirtings etc., and repainting).

This is a part of a major renovation though and costly.

2. Flexible sealant.

Allows for movement and much cheaper.

I am inclined to initially use flexible sealant (as a cosmetic solution, eg, to present to new tenants) as I am not convinced yet that the movement issues can be resolved.

The property is on reactive clay soil. Although work is planned for this property to fix other potential causes of movement, fixing these may simply minimise movement and not eliminate it all together (cracks will need monitoring over a period of time to assess this ?12-18months). Thus any crack repair, even if done well, may still crack again.

The only thing that remains if this option is taken is,...what will it look like???

It is an old house, it has character, and many imperfections too...so I would not expect it too look that great, just acceptable and less frightening than having huge cracks through your living area or bedroom wall.

Does anyone have any photos of what a crack filled with flexible sealant and then painted over looks like??? myla?, before/after shots?

Any other comments appreciated.

Cheers,

GSJ

hello gsj

will see what I can dig up as do not have digi camera

the cracks will probably need some sanding as may of moved out as well as open

need flat or low sheen paint and several coats or seude affects etc

everything needs to be allowed to dry correctly ie. seal one day, paint 1st coat the next etc

thankyou
myla

Thanks Myla, any photos would be good.

I just read in a previous thread regarding expansion joints.

Is there a role for expansion joints (or I think also called ´articulation joints or control joints´ in the cracks seen in the photo shown previously? Can they be painted over, and how would they look?

Could someone explain what these are and when/where they are used?

Thanks,

GSJ

Expansion joints will look ugly in that application.
Expansion joints are normaly used in stair wells between floors of buildings. Or in commercial projects where there are long coridoor ceilings or walls. Usually installed at critical points in the building adjacent to other structual expansion joints.

The flexible sealant option can surley only be seen as a very temporary solution. I cant say I have ever seen this done where the cracks are not visible afterwards, I have seen many attempts that have gone horribly wrong.

Here is a crack repaired with sealant that has shrunk back. Also a typical expansion joint use.


Attachment 29134Attachment 29135

Cheers
Rod

Quote:

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Originally Posted by rod@plasterbrok

Here is a crack repaired with sealant that has shrunk back. Also a typical expansion joint use.


Attachment 29134Attachment 29135

Cheers
Rod

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Hi Rod,

Thanks for all your replies on the various threads to vother members thread (including mine;)). Saying that how would you (as an expert in this field) go about correcting the crack in the picture you uploaded?.

The reason I ask is that I have several cracks starting from the corners over the door (as shown). It would be nice to get it fixed on the first attempt rather than run into the problems other have encoutered here previously.

Kindest regards
David

With this type of crack, which is in plasterboard, I would use wet and stick paper tape as described in another thread here, on fixing cracks in ceiling joins.

There is no need to dig out a crack in plasterboard as descibed, for cracks in render or lathen plaster.

Cheers

Rod

Rod, thanks for the clarification re. expansion joints.

The photo there of the crack repaired with sealant looks quite bad, certainly not the cosmetic outcome I am looking or.

I hope Myla or others can dig up some photos to show a better outcome than this.

If not, I may have to initially just do a good crack repair as you suggested Rod, and also attempt to fix potential causes of movement and thus minimise future movement and repeated cracking.

GSJ

I read another thread in the forum where someone was attaching plasterboard sheeting to something called ´furring channels´, effectively creating a wall that moves with any future movement in foundations...see the quote below -

´therefore intend sealing wall sheets to furring channel (allowing sheets to move up and down on walls) and also sealing wall sheets to floor...´

Anyone have any comments re. this, I presume it would be an expensive process.

GSJ

Here is a post that appeared on the somersoft.com forum for a potential approach to cover up cracks, I think it is like the ´furring channel´thing I mentioned in the previous post.

´One rather expensive solution could be a gyprock wall set on resilient mounts and rails.

First you would need to attach resilient mounts on the wall at meter intervals. These mounts cost about $3.80 each, they are metal with a rubber insert specifically made to not transmit vibrating sound. You then attach rails to these mounts in a vertical direction and attach the Gyprock to the rails.

In this wall you should effectively have a floating wall as the rubber in the mounts will allow the movement of the brick wall without cracking the gyprock.

Doing this you would loose about 45mm so would only be practical in end walls running to other walls.´

Any thoughts/comments?

GSJ

Just to add to this thread, some more contributions from the somersoft.com forum.

Another method suggested here is to cover the cracks with a thin timber strip, then paint over. This is very cheap, simple and will allow for movement. However, again the issue is appearance. Although the cracks will be hidden, the strips will still stand out, I presume.

Has anyone here used this approach, and if so, could you post any photos to show how it looks???

Here are two posts regarding this from somersoft.com -

(1) ´While not the best look, the best solution i have found is a cover strip such as a 50mm by 12mm timber strip nailed over the crack and painted the wall colour. This allows for movement behind it.

Occasionally the wall may move to the point where it will need touching up with the wall colour but the crack will stay hidden.´

AND

(2) ´As an interior designer, we used quite a few of the Rondo jointing profiles/strips, one of which is used to join two walls, allowing for future independent movement.

http://www.rondo.com.au/rondo/

At the end of the day you will see a joint, but it is a slight shadow gap without any large protruding beading, plus the edges of each side are taped and joined neatly. A nice solution to a tricky problem!´

I will see if I can ask ´Rondo´ for any photos of this product.

Thus far the 3 cheapest/simplest solutions to this problem of cracking are:

1. Flexible Sealant
2. Thin timber strips (as mentioned in this post)
3. Repair the crack properly (as Rod has mentioned previously)

GSJ

"(2) ´As an interior designer, we used quite a few of the Rondo jointing profiles/strips, one of which is used to join two walls, allowing for future independent movement.

http://www.rondo.com.au/rondo/

At the end of the day you will see a joint, but it is a slight shadow gap without any large protruding beading, plus the edges of each side are taped and joined neatly. A nice solution to a tricky problem!&#180;"</QUOTE>

This is refering to expansion joints.

The timber option may be ok if the cracks where straight and the strips could be applied in a symetrical patten, that makes it look like a feature rather than a cover up.

The resilient mount option would definitly do the job, but as they say it is an expensive option. It is for you to decide on how much you want to spend vs the desired outcome.

The desired outcome will possibly be dictated by, factors like:
a/ How long you intend to keep the house
b/ Will what I do add to the value or detract from the value?
c/ Can you accept a less than perfect result?
d/ Will you need to repeat the process again in X number of years?

After weighing up all all the options here you should have enough information to make a well considered decision.

Cheers Rod

Thanks Rod and others for contributing to this thread.

Clearly, there are many options for a cosmetic solution to the problem of cracking in internal walls, each with their own pros and cons.

Will post an update of what happens with this house in due course.

In the meantime if anyone has any further ideas please add to this thread....

Also, if anyone has any before/after photos to show the methods they used to cover up cracks, please post them on this thread!!!

GSJ

Rod and others, just a thought...

If you used the flexible sealant option, to improve the appearance, instead of painting over directly with several coats of suede/textured paints, could you not then put fibreglass/paper tape on top of it, and then paint over this???

GSJ