Let’s talk lime plaster, which has a lower environmental impact than cement, and is comparatively nearly carbon neutral. Lime plaster has been used for years (don’t ask me how long, I’m crap with history), as a binder in mortars, plasters, and paints. The one drawback of lime plaster when compared to other quick drying cements is that it takes a lot longer to cure. But the most remarkable benefits of it are that it’s a very eco-friendly material to work with (which is preferable nowadays). It’s also easy to work with, breathable and entirely self-healing. It’s generally used to cover strawbale and wooden walls (and not recommended to cover external clay plasters in places where it’s going to be subject to a lot of water/rainfall/moisture). Another really useful benefit to note is that it can be kept as a putty for as long as you need (by covering it with a little water) and that once cured, it’s naturally mould and mildew resistant! Which when considering the way we live today, is a pretty amazing thing.
Things to note with Lime plaster are that’s its a bit more dangerous than regular types as it can burn the skin. Make sure you wear full protective gear whilst using it (this means the really attractive full elbow length rubber gloves too, don’t take chances with alkaline based burns) and make sure you clean your tools carefully afterwards too.
If you’re going to use lime plaster to cover strawbale walls, experts recommend around 3 coats but you’ll need to allow 4 days or so between coats and be advised it’s not the sort of product you can find easily. It requires some knowhow with handling, mixing and using so you’re best off to call a professional when it comes to plastering if you’re a novice. But it’s definitely a good eco friendly alternative if this is something you’re after.
You can find out more about lime plaster here.