Hello all - I am in the midst of a home improvement project, and one of my tasks is to build stars (2 treads) from my garage into my mud room. I want to make the stairs out of cement. I will be making the form from plywood and 2x4s, and then pouring the cement into the form. Once the concrete sets for a few days, I of course plan to pull the form off. My question is, do I need to do anything special to the wood to keep it from sticking to the cured concrete, or will a few whacks of a hammer break the seal.

Thanks.
Rob

Wipe the form surfaces with vegetable oil or clean motor oil.

Wipe the form surfaces with vegetable oil or clean motor oil.

Will do - I assume that won't leave stains on the concrete surface, will it? Interesting technique. Is that what the pros do, or is there a commercial product they use?

Thanks

We use something called 'formply'. It is a faced plywood that leaves a super smooth concrete finish . Pretty well any building centre should have it - if they don't call it formply, then ask for faced plywood to use for concrete forms.

Don't forget the vibrator - it'll make sure there are no bubbles.

There is a commercially available form oil but you don't need it. Ballenger's veg oil is adequate.
A vibrator would be great but for just two steps I think you can consolidate this depth with a good trowel, cutting into the poured concrete and compacting it as much as possible.
Tapping on the outside of the forms on all sides helps to consolidate it also a technique for external vibration, removing trapped air. Some type of edging tool would be good for the top front edge of the tread and possibly for all exposed edges to prevent spalling.
Keep some wet rags on all exposed surfaces for a few days to help prevent cracking from drying out too quickly, especially in hot weather. We always broomed the treads creating lines (about 1/16 inches deep) from side to side (long ways) to roughen the walking surface, as the last part of the finishing process.

Cheap tip - If you can't work the air out by tapping the forms and you don't have a vibrator, you can use a vibrating palm sander on the outside of your forms. It will work fairly well on a small pour.

Thanks everyone! A lot of good advice. Looks like I'm ready to start pouring.