A reader's General Construction question: Concrete timber treads?

Kerry B.   from   New Zealand   had this concrete timber treads question.

Hi, great site you have here Bill. I hope you can help me with a project I have to do. Namely, covering old concrete steps above a wooden deck. 2 steps are above the deck, rest are below it.
How do I go about covering them over with new wooden steps?
How do I secure timber frame etc? Do I just lay some treated timber directly onto concrete steps and then add decking timber?
I also have a concrete back door porch area, 1 step to the ground and would like to cover this over also but a unsure how to start. Hope you can shed some light on how this is done?

Bill's answer

Hi Kerry,
Thanks for the kind comments about the site.
Covering concrete steps with timber. I have to be a bit negative here, sorry.

• Concrete steps are great out doors - no maintenance. Why change?
• Main point (unless you have done some allowance for this) you will change the riser heights of the stairs. Adding 20 to 45mm to the bottom riser, and reducing the top one by the same amount goes against the basic rules of stair design. All the riser should be equal.
• The interface between the timber and the concrete will tend to hold moisture, promoting rot.

So if the old steps are too ugly looking:

• Chop them out and replace with steel and timber. (expensive I know.)
• If the height problem is not too bad, use decking the same as your actual decking timbers (20mm), with same spacing as the deck. I'd fix with plastic Rawlplugs and SS countersunk screws.
• Put plenty oil and preservative on them before fixing. That means on the places that will never be seen.