Pre-Cast Stair Treads
Pre-cast stair treads made out of concrete are probably one of the best exterior stair steps available today, as long as they're installed correctly. The picture below provides you with a row of concrete pre-cast stair treads that should have been moved away from the stucco. A little gap between the stair treads would have done wonders for this building in the future.
Pre-cast Stair Tread Tips
1. Make sure that the stair treads are level. It wouldn't be a bad idea,
to have a few extra flat washers, with you in various sizes, to help
with any adjustments. It's not uncommon to have slight variations in
most stair stringers, whether you're planning on using metal or wood
stringers, with metal brackets.
2. The alignment is critical, so make sure that each pre-cast stair tread is positioned properly. This is a big problem and I run into it often. Stair treads that aren't perfectly Straight, at angles or out of alignment, create problems for people, using the stairway.
3. Make sure that you examine and inspect your staircase regularly. I've seen some incredible damage to precast stair treads that create safety problems. Replace any damaged parts as soon as possible.
4. Now for the biggest problem I've ever found as a stair builder, with pre-cast treads. Make sure that there is a gap between the stair treads and your wood stringers or walls.
These treads should be fastened securely to the metal brackets or stair stringers, but shouldn't be touching anything else. I've actually made a lot of money, repairing these mistakes.
I replaced about 50 stairs on one apartment complex, because the concrete stair treads were touching the wood stringers and the ones that weren't, usually had debris, in between the treads and the stringer.
Here is what happens, the debris or the concrete will retain moisture and it will retain moisture for long periods of time, especially if the stairway is located in the shade. Get this, most exterior stairways, for apartment buildings, have some type of covering, over them.
For those that don't, you're still going to have a large percentage of them, in the shade, for long periods during the day. All you need is a little moisture in the air, one sprinkler spraying on the stairway regularly or a rainy climate, to create mold, mildew, fungus and wood rot.