External Wall - Options for Smooth Rendered Finish

rampantbunny

Looking for options for external wall so that the finish is smooth and more repellent of dirt.
This is for a boundary wall in proximity to a busy road. Neighbors walls are always covered in dirt and dust. A power-wash is required to clean down but it's usually a paint job required afterwards. I'd like to try and avoid that or at least extend the time between maintenance. The required color of the wall is white which is not ideal but that's the brief.

Questions:

1. can standard sand/cement based plaster be finished smoothly on a wall (think steel trowel)
2. will a smooth finish make it difficult for paint to get a good key (thus defeating the purpose)
3. are pre-colored renders a better bet

tedimc

rampantbunny wrote: »

Looking for options for external wall so that the finish is smooth and more repellent of dirt.
This is for a boundary wall in proximity to a busy road. Neighbors walls are always covered in dirt and dust. A power-wash is required to clean down but it's usually a paint job required afterwards. I'd like to try and avoid that or at least extend the time between maintenance. The required color of the wall is white which is not ideal but that's the brief.

Questions:

1. can standard sand/cement based plaster be finished smoothly on a wall (think steel trowel)
2. will a smooth finish make it difficult for paint to get a good key (thus defeating the purpose)
3. are pre-colored renders a better bet

I’m sure you have - but have you looked into the Sto renders? They offer some self cleaning renders and paint which may be of interest. The render may not be smooth enough for your needs though.

listermint

rampantbunny wrote: »

Looking for options for external wall so that the finish is smooth and more repellent of dirt.
This is for a boundary wall in proximity to a busy road. Neighbors walls are always covered in dirt and dust. A power-wash is required to clean down but it's usually a paint job required afterwards. I'd like to try and avoid that or at least extend the time between maintenance. The required color of the wall is white which is not ideal but that's the brief.

Questions:

1. can standard sand/cement based plaster be finished smoothly on a wall (think steel trowel)
2. will a smooth finish make it difficult for paint to get a good key (thus defeating the purpose)
3. are pre-colored renders a better bet

You'd want something like a silica silicone render . Acrylic renders.

These are self cleaning.

Have used a brand called Alpol myself. Excellent stuff and super easy to work with.

rampantbunny

tedimc wrote: »

I’m sure you have - but have you looked into the Sto renders? They offer some self cleaning renders and paint which may be of interest. The render may not be smooth enough for your needs though.

'I’m sure you have...' sorry tedimc, don't get it!

Just checked out the Sto products. 1.5mm grain is smallest but they recommend 2mm for better water shedding which means the self cleaning effect is better as water sheds faster. Wouldn't have thought that myself but that's the logic it appears.
So smooth finish is not essential.

As for the Alpol products.. big range available. Need to spend some time sifting through but in the meantime listermint; did you apply a product over a sand/cement base or was it Alpol only?

Yellow_Fern

It is a pretty wild alternative but one solution to this problem I read was on a beautiful renovation in Kerry. They wanted coloured concrete but it was too pricey so they innovated using iron oxide soil fertiliser which gives a beautiful dirt free rust colour.

https://www.irishtimes.com/life-and-style/homes-and-property/it-s-a-long-road-to-kerry-s-lost-cottage-but-oh-when-you-get-there-it-s-beautiful-1.3529157

rampantbunny

Yellow_Fern wrote: »

It is a pretty wild alternative but one solution to this problem I read was on a beautiful renovation in Kerry. They wanted coloured concrete but it was too pricey so they innovated using iron oxide soil fertiliser which gives a beautiful dirt free rust colour.

https://www.irishtimes.com/life-and-style/homes-and-property/it-s-a-long-road-to-kerry-s-lost-cottage-but-oh-when-you-get-there-it-s-beautiful-1.3529157

Don't think I'll experiment with the aged look because it wouldn't fit with what I have currently. Interesting read though nonetheless.

Proprietary products as mentioned above prob cost more than sand/cement alone..maybe not. Or there's probably a specialist paint based solution that can be applied. There's multiple products for everything for sure.

listermint

rampantbunny wrote: »

'I’m sure you have...' sorry tedimc, don't get it!

Just checked out the Sto products. 1.5mm grain is smallest but they recommend 2mm for better water shedding which means the self cleaning effect is better as water sheds faster. Wouldn't have thought that myself but that's the logic it appears.
So smooth finish is not essential.

As for the Alpol products.. big range available. Need to spend some time sifting through but in the meantime listermint; did you apply a product over a sand/cement base or was it Alpol only?

it comes with its own base mix which is applied first then the render finish goes on top. Can choose any colours. would buy the stuff again if had future jobs it surprised me how easy to work it was and im a totally amatuer platester.

theres a guy supplies the stuff on done deal. look up Steico i believe he sells that also.

BryanF

Microcement ?

rampantbunny

BryanF wrote: »

Microcement ?

Possibly. Just from looking this evening I haven't seen any example applications on external walls. Mostly internal walls, floors, bathrooms. Waterproof so external use maybe.

One thing I'm bearing in mind is that the man who will do the job is old school plasterer. He's in the family so one of those jobs thrown his way to keep him ticking over. So something applied over standard sand/cement render suits 'us' best.

rampantbunny

I'm not pushing either of these products but they look suitable for what I want. For boundary wall:
StoColor Lotusan
A unique self-cleaning facade paint, suitable for masonry and rendered surfaces. Water and dirt is unable to cling to the surface, so every time it rains the facade is simply washed clean.

I've also got some reinforced concrete to coat and the following looks like a good fit.
http://www.alpol.pl/en/katalog_produktow/go:25:235


Thanks all for the advice/recommendations!