Help!! Blueboard wall is cracking up

shackonthehill · Mar 04, 2012 3:03 pm

Hello everybody.

I have an ongoing problem with the blueboard wall we erected as a privacy screen due to the excessive demands of our neighbours.

The privacy wall we erected is timber frame clad in blueboard.
It was erected by the tradies who did our decking and alfresco area. The finishing and painting was up to us.

Due to a male only family reunion of 3 generations happening at our place , the wife made me plaster up and paint the blueboard wall in a rush before I flew back to work and miss the reunion. ::angry::

This was probably bout 12 mths ago.

When I plastered the joins between the sheets and the edges , I went to bunnings and purchased what was supposed to be and all weather plaster type filler.
All of the edges of the sheets were recessed so I freehand filled the joints and I freehand did the edges as well.
After all the sanding was done we painted the entire wall in a texture paint (essentially paint with sand in it!!)

The end result was absolutely fantastic!! It actually looked just like a rendered and painted brick wall. I never thought that would have been possible. ::cool::

Now the fun part starts.

I knew, that as the wall was a timber construction, there would be a certain amount of movement would occur. This has happened and as a result there are minute hairline cracks forming between the joins. Small, yes! but noticable enuff.
Is there a flexible filler or goo the I can apply that will ensure a continious look across the sheets? This goo will need to be paintable by the texture paint. I am happy enuff to grind out the joins with a crinder to effect the repairs.

The other part is the all-weather plaster in the edges are begining to dissolve in the weather.
I didnt use the edging stuff as I free handed the edges but I cant help but think that wouldnt make a difference to the filler dissolving.

Is there a filler I can use for the edges, that will survive the weather? Whats it's name? where do I get it from?
Or do I have to use real cement to do the edges??

Does anyone have any suggestions or solutions so I dont have to redo the beloved wall on a yearly basis??

Cheers Ddgy Roger

mgilla · Mar 04, 2012 4:03 pm

Hi Ddgy Roger,

A couple of questions, did you take the joins before you applied the filler. If you dont use the gauze tape they will crack regardless of what filler you use.
The other thing is, was it a flexible joint filler? There is always going to be movement, so the product you use needs to be able to flex.
What kind of water protection do you have at the top of the wall? you will find rendered blueboard will not keep the water out if it allowed to sit on it for any length of time. You can get a metal cap of any size you need bent up from somewhere like Stratco. There not that much at all.
I did a blueboard fence recently, taped all the joints then used an acrylic render over the top. The renderer then came along and went completly over the top. Although the client still hasn't painted it after 3 months it is still all in tact.
You will need to grind the joints out and retape and set them if you want to fix the cracks. The thing will be blending in any new work with the existing.
My thought is, if there only hairline cracks, unless your prepared to rerender the entire fence. That any patching you do will stand out way more than the cracks do.

Cheers

shackonthehill · Mar 04, 2012 11:51 pm

Hi Mgila,
Thanks for your response mate.

I hadnt used any gauze tape on the joints, just straight filler.
So it seems to me that I have to grind out the joints between the flat sheets and then use the gauze tape then use the acrylic filler that you mentioned. Is this about right?
Repainting the whole wall was always on the cards.

What is the name of this acrylic filler? Where do I get it? how much will I get slugged for it?

The ends and the top of the wall is thin strips of blueboard butted up to the flat sheets.
What would be the best method to use here?
Do I use the gauze tape around the edges or do I use the edging strips the plasterers use , then use the acrylic filler. Or do I free hand it again?

The wall itself is not rendered as such, but is painted in texture paint to give the appearance of a rendered wall.

So far your help has been invaluable.

Cheers Ddgy Roger

ps for some reason I cant put the "o" into the first half of my nickname as it comes up as an offensive word!
Go figure??

stormjr · Mar 05, 2012 12:13 am

If the blue board is butted up against something and you need to fill a small gap then maybe you could use a flexible paintable silicon, should be water tight so won't wash away, just be sure it says paintable on the tube.

mgilla · Mar 06, 2012 7:50 am

You can get the acrylic render from bunnings for about $10 per bag, that will be heaps just to set joints.
It has a very fine texture so once you put it on and get it reasonably flat with a trowel wait for it to almost dry then smoothe it off with a wet spounge. If it has gone off on the edges use a spray bottle of water to bring it back up so you can finish it with the spounge.
Just do a small bit first and get the finishing of right. If you do this bit in the sun it won't take long to dry.

Cheers

shackonthehill · Mar 06, 2012 10:37 am

thanks fellas.

That gives me a bit of an idea of what to do and what to use to be able to do it.

It will take a copule of breaks away before I get it done.
Will let everyone know how badly I stuffed this one up. lol.

Cheers Ddgy Roger

cherub · Mar 07, 2012 5:19 am

Depending on the look your after you could use a capping for the top and sides, either timber or stone and finish up to that [no corners]

builditupandunder · Feb 24, 2014 9:21 am

Magnesium Oxide Board would have been the best option if you were to start again.

Blueboard is old technology and is expensive, heavy, hard to work with and not really water proof. (if you immerse in water for 2 days it will turn to papermash)

MGO board ive used on heaps of projects and is an awesome product ! google it and see what im talking about

up to a few months ago i had only used blueboard on all my projects, we used blueboard on the outside of my up and under renovations. I just accepted that was the price we had to pay for blueboard like everybody else i thought blueboard was the only option for a strong water proof cladding for outside and inside.

but....... im all about reducing my costs on every home renovation me and my partner to and the blueboard bills just kept going up.
then i found MGO board (magnesium oxide board) boy what a mouth full ! MGO comes in all sizes and thicknesses.

just google "MGO Board "or wikipedia it and you will see what im talking about -

ausdesign · Feb 24, 2014 7:40 pm

2 days - wow. Who'd have thought it. !

mgilla · Mar 15, 2014 2:30 pm

ausdesign

2 days - wow. Who'd have thought it. !

My first thought also, been using it for 30 odd years and never once seen it turn into a head wrapped around a balloon.