Cladding or render for updating limestone wall?

[DIYH]

Hi

I'd like to update the look of this old limestone wall on your left. Initially I thought I'd like to render it but read limestone can't be rendered. Although if it's sealed is it possible?

I've also seen the below images of fibre cement cladding. Would this be a better option? If so, what would be the best way to attach and also do the edges/corners? Is it ok to cut to size with a circular saw?

Is exterior paint ok to use on the cladding?

Many thanks!

 

Many thanks 

 

 

[JacobZ]

Hi @DIYH,

Rendering limestone is possible, but in your situation I wouldn't advise it because you would need to seal it from the back of the retaining wall to ensure water is not coming through the stone. It would last for a while, but ultimately, due to the porosity and likelihood for moisture seeping through the stone, it would likely fail prematurely. If you wanted to render the stones, I would suggest speaking with a renderer for their recommendation as it would not be as simple as just applying render over the top.

If you wanted to clad the stones with fibre cement sheeting, you would need to batten out the stones with something like 70x35 H3 framing, with plascourse stapled to the back edge of the framing to prevent direct contact with the stone. You could then attach the fibre cement sheeting to the battens using fibre cement screws.

For finishing the corners and edges, you would generally use trims like this PVC Cap Mould or PVC Exterior Angle, depending on the thickness of the sheeting used.

FC sheets can be cut with a circular saw using a fibre cement blade, although it is not recommended without a suitable dust extractor and respirator as it will create a lot of airborne dust. You would be better off using fibre cement shears, a Fibre Cement Sheet Cutter, or scoring and snapping it with a Score and Snap Knife.

It is worth mentioning, that while using these materials for this kind of project is fairly common, it is not their recommended use and suppliers like James Hardie would not offer any kind of warranty on their product if it was installed in this setting. If you are happy with this, nothing is stopping you from using them, you would just need to be aware that you would do so at your own risk.

Let me know if you have any further questions.

Jacob 

[DIYH]

Thanks Jacob, I appreciate that detailed reply.

Any better suggestions than my idea of the fibre cement to clad? The top edge of the limestone wall is going to have a pool fence attached to it so ideally don't want anything too chunky. Open to options! 

Thank you again ☺️

[Jason]

Let me tag a few other members to see if they can share their thoughts @DIYH.

@Dave-1, @JoeAzza, @Nailbag, @AlanM52.

Jacob will be back on the site on Friday.

Jason

[Dave-1]

Good Morning @DIYH 

That will be a nice area for a pool for sure. With your want for a pool fence on top of the wall my thoughts head back towards a render over the existing stones. Which means that you would have to dig out the soil side of the retaining wall and seal it first. If there is no drainage on the rear of the retaining wall then it would be perfect for killing two birds in one go.

That 4mm Hardi plank sheeting is very flexible (wouldnt suggest that one, I used it as a backer and yeah it needs supports) The thicker version would be far better. With fixing the pool fence through the cladding and a batten, it adds easy failure points, thats why I am thinking of going back to keeping it simple as possible.

Dave

[EricL]

Hello @DIYH 

There was a similar query awhile back and they were looking for an alternative cover as well. Using the 70x35 timber framing that Jacob suggested, I recommend covering it with SpecRite 90 x 19mm Merbau Pre-Oiled Decking - Random Lengths. This type of cover gives it a natural look and allows the limestone to breath and does not trap the moisture behind it. It's easy to cut and format plus, will provide a long service life. 

If you need further assistance, please let us know.

Eric

[DIYH]

Thanks Eric, that's a good suggestion. Just wondering if I could attach the decking boards to the front of the wall and still render just the top section after applying a sealant. It's approx 250mm wide. It will mean the main front part would be breathable through the decking and the render would work with not too much height added on the top of the wall under the pool fencing.What do you think?

Thank you! 

[EricL]

Hi @DIYH 

There should be no issue with having the decking boards at the front. But rendering the top section has me a bit worried because of moisture and condensation. I advise following @JacobZ recommendation and sealing the limestone from the back so that there will be no chance of moisture contaminating the render at the top. 

Upon reflection, your limestone wall will only gain an extra 50mm if you were to clad both the top and side of the wall. I recommend having a think about it and how it will impact your pool fence. 

If you need further assistance, please let us know.

Eric