rendered flower bed damp issues

[Wass87]

Hello all,

Hope you are all well and keeping safe!
I am currently int he process of landscaping my garden and wanted to put in a rather large flower bed I did consider using railway sleepers but i like the look of rendered block-work. I wanted to render the retaining wall and flower bed with no coping stones on the top.

The flower bed will be approximately 500mm in height i am not able to incorporate a DPC as some have suggested online as it would effect the integrity of the wall and flowerbed (and i generally believe that it wouldn't be any help).

I have read that people have had damp issues and render falling off and crumbling away after a winter or two. I wanted to know if anyone is aware of a product that i can use to help waterproof the flower bed and wall from rising damp.

I am aware that i can use a DPM in the flower bed to stop the moisture from the soil penetrating the wall and incorporating weep holes and laying 100mm of gravel for drainage.

i wanted to know if anyone has done this and if the render has lasted? i don't want to go through the hassle and expense for it to look horrible in a year or twos time.

Are there any other solutions available?

Thanks for reading and i would appreciate any help provided!

 

[freddiemercurystwin]

Screw some cement board to the face of the wall and render over that. Apply some epdm membrane to the rear of the cement board first.

 

[Wass87]

thanks for your reply Freddie, sorry if i'm being a little special here but what benefit does that provide exactly?

 

[freddiemercurystwin]

Well cement board with an edpm membrane applied to the back is pretty water resistant if not waterproof. Keep the bottom of the cement board/render just above ground level.

Or another novel approach could be apply a dpm to the wall with some vertical battens to create an air gap, then the cement board + render, this assumes you have a coping stone or similar on top of the wall to hide the gap. Stop the cement board just above ground level and 10mm gap under the coping to allow for some ventilation.

 

[Wass87]

I've not heard of that before but it does make perfect sense. I was hoping not to have a coping stone but if it means not having a deteriorating render wall after a year than a coping stone it is! Thank you very much Freddie, i may give this a go and see how i get on.

 

[noseall]

I have read that people have had damp issues and render falling off and crumbling away after a winter

The problem with the idea of rendered beds in this country is they rarely take into account splashy rain, British winters and north east facing elevations. All looks great in magazines with beautiful garden images from Italy and Spain or the freshly completed British ones.

None will show you the moss covered, rain splashed ones with blistering paint and failing render.

 

[freddiemercurystwin]

Well what do you think of applying the render as a rainscreen cladding nosey with a vented cavity behind? How's that different to a standard wall detail?

 

[noseall]

Well what do you think of applying the render as a rainscreen cladding nosey with a vented cavity behind? How's that different to a standard wall detail?

I'm not knocking render per se, although I always point out to customers that some elevations will fare better than others. Rather, I'd discourage render finishes in certain locations. We have all seen a rendered wall with a dripping gutter above (splash stains etc) and the God awful mess it makes of the render. Imagine being daft enough to introduce render where this is going to happen almost everywhere.

 

[freddiemercurystwin]

For sure my method may suffer a little as you describe but it'll not suffer the typical failings of merely rendering the face of the wall directly ie blown render and flaking paint.

 

[noseall]

For sure my method may suffer a little as you describe but it'll not suffer the typical failings of merely rendering the face of the wall directly ie blown render and flaking paint.

I'm never convinced by the whole positioning of render close to splashy soil either. Soil is rammed with non-friendly contaminents.

I'm a bit sceptical, as you can tell.

 

[Wass87]

The problem with the idea of rendered beds in this country is they rarely take into account splashy rain, British winters and north east facing elevations. All looks great in magazines with beautiful garden images from Italy and Spain or the freshly completed British ones.

None will show you the moss covered, rain splashed ones with blistering paint and failing render.

Thank you for your reply, this is my concern. The longevity of the look of the wall and i must agree that even though Freddies solution sounds pretty good, overall i will have a stained render wall. I didn't want to add a coping stone and i think i may just go with the sleepers instead. Less faff and i wont be feeling sorry for myself in a few years time like i will with the render.. decision now is do i go with the green tanalised or brown to go with my kandla grey sandstone patio

 

[Wass87]

I'm never convinced by the whole positioning of render close to splashy soil either. Soil is rammed with non-friendly contaminents.

I'm a bit sceptical, as you can tell.

lol, i'm also not very convinced after seeing pictures of before and afters , i'm thinking i don't want to find out the hard way ..would end up crying after all that work only to find out its gone to pot after one typical British winter! lol