hi i want to render over the back of my house the render that is there now is sound but just ugly what is the correct mix and preperation for this also would i use the same trowel as id use for normal plastering and finishing
Power wash down using a fungiced solution following instructions. This will kill any algae and alos wash off any loose material. Look at our mortar mixes project for render mix and use lime in the mix to avoid sealing in any damp which is already in the existing render. If you seal it in with cement based render on top the damp will work its way inwards.