´Covering up´ cracks in internal walls - FLEXIBLE, WATER-PROOF, GYPROCK?

[JIT]

Hi all,

A friend of mine has a single-fronted, semi-detached, Victorian-era period home (c1900), in the inner northern suburbs of Melbourne.

Due to a number of factors (reactive soil in the area, large trees on neighbouring properties etc...) there are cracks through several of the internal walls (and external walls too), up to 1cm wide in some areas.

A recent Archicentre building inspection has noted these cracks to be quite significant, but common amongst properties in the area and of this age. Essentially, the house is not expected to fall down, but fixing the cracks permanently is very unlikely. Restumping, underpinning etc...may still not prevent further cracking.

My friend has done some basic things like removing a large tree in the rear yard close to the rear and side wall, and improving subfloor ventilation, as simple ways of helping to reduce the problem of cracking. They are considering a new damp-proof course, but this appears quite expensive, and as it is an investment property, she is not keen to do this at present.

The property is rented out at present.

The question here is -

What can be done to cover up the cracks, cosmetically?

ie, given that permanently fixing the cracks is unlikely, what can be done to improve the cosmetic appearance of the walls?

The simplest thing, I presume, is filling the cracks with plaster and repainting...but with a change in climate and further movement, they will obviously just re-open.

What about the following?

Is it possible to put a new gyprock plasterboard over the existing walls to cover the cracks? If there is ongoing movement, then, I would guess that the new gyprock itself could also crack?

I have seen a 'flexible gyprock´ product used for curved walls. Has anyone used this before? Would it be possible to use this flexible gyprock on a straight wall instead, and so, if there is any movement, the gyprock has some flexbility and so therefore may not crack??? Just an idea, not sure if this could work???

In addition, using a ´water-proof´plaster board may help with rising/falling damp probelms...?

Any thoughts or ideas would be much appreciated...

GSJ

 

[rossv]

Hi GSJ,

I don't see any kind of gyprock over the top solving the problem.

A fibreglass tape set over the crack will solve the problem up to a point but still will fail eventually.....

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.



rossv

 

[gerd.]

Hi GSJ

I have found that when large trees or extensive vegetation is removed from surrounding walls, it can take up to a year for the subsoil to stabilize as it will need to take up moisture previously removed be the plants. During this period of stabilization some movement of the walls may occur.

As for damp course rectification the product I use is TROJAN Waterproofing System.
It is a polyester polymer with a water carrier it will waterproof the mortar & brick

You can find more info at . http://www.enviropacific.com/home.html

Gerd

 

[handyandy]

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.

Cheers

 

[AlmostBob]

I have seen a 'flexible gyprock´ product used for curved walls. Has anyone used this before? Would it be possible to use this flexible gyprock on a straight wall instead, and so, if there is any movement, the gyprock has some flexbility and so therefore may not crack??? Just an idea, not sure if this could work???

a bummer but no, its only flexible about the the plane of the sheet, it will bend but not stretch, and after its bent and dried the bend is set, further bending requires the board be wet again to soften the paper and plaster and make it flexible.

gyprock

There might be a good case for timber veneer (like 1 ply of a plywood sheet) or pine panelling in those rooms

 

[JIT]

Solutions...

Thanks for the replies so far...

AlmostBob, sounds like my gyprock idea is not so good. The timber veneer and pine panelling... are these materials that will bend/stretch? Do you mean putting this material on top of the existing wall and no gyprock? Then painting it...

Any more ideas appreciated...I think if a good solution can be found it would be a great way to add value to properties people may normally stay away from, but still have great investment potential due to location etc...

GSJ

 

[lowb]

hard to visualise, i havent seem something like this before.

wonder what would happen if you put cement inside the cracks?
would that work -just a stab at it

 

[Rach]

Hi GSJ,

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.


rossv

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!

Rach

 

[JIT]

Thanks Rach,

Do you have any photos that you can show of a crack covered up with this method?

There is a thread on the forum at www.woodworkforums.ubeaut.com.au, called ´Covering up cracks in internal walls´ (in the plastering sub-forum), a photo of this would be good to add to that thread, as many options of covering up cracks are discussed here.

GSJ

 

[Rach]

Thanks Rach,

Do you have any photos that you can show of a crack covered up with this method?

There is a thread on the forum at www.woodworkforums.ubeaut.com.au, called ´Covering up cracks in internal walls´ (in the plastering sub-forum), a photo of this would be good to add to that thread, as many options of covering up cracks are discussed here.

GSJ

No, sorry. Home on maternity leave at the moment! Check out the Rondo web site or give them a call and they might have some examples for you to use.
Rach

 

[plumtree]

Are these cracks too wide for somthing like 'No-more-gaps' silicone sealer. We have used this on fairly large cracks. When used on white ceilings it can be renewed as required and touched up with a bit of ceiling paint.

 

[JIT]

The cracks are up to 10mm.

Plumtree, with ´no more gaps´, after painting over, does it look OK?

GSJ

 

[see_change]

While it might be fine with new walls to set them up in a way to have movement joints , I have the same problem at my work. Longer walls with multiple cracks . Then have been filled on at least two occasions ( with fleixible filler ) in the last 18 years but have ended up cracking again fairly quickly.

I was wondering if it's possible to do what they do with Concrete driveways , ie put cuts in the render , so you can determine where the cracks will occur, and then put some form of cover over them ( as suggested by ross ) to hide this . This might make the problem more localised and hopefully more asthetically managable.

Any thoughts from the renderer's, builders out there ?

See Change