To begin, I removed the steps. I used a circular saw to cut each stair down the middle. I then took my hammer and hit each part out of the dado created for each step. There were about five huge nails in each side of the stringers holding each step. Total over kill. I then took off one stringer and slide it out of my way. I cleaned and then painted the wall with a basement waterproofing paint. The wall was in good shape which meant I only had to fill in a few cracks with mortar.
Under our stairs there was a makeshift shelving system. I've always hated it and planned to redo it someday. Someday was Saturday. Discovered the entire stair system was being held up by two 2x4s! We dodged another bullet there. I beefed up the supports under the stairs with 4x4s and a studded wall. The stud wall really gives the entire platform good support now.
The wall was again treated with insulated foam board. This was also put behind the shelves.
The last step was to measure and cut new steps. The new steps were 29 1/2" wide. After a little trouble, I got them all in. I added 2x4 supports under each step to give them more strength. The steps will be carpeted so I used regular 2x10s for the stairs. If we wanted, we could have installed oak stairs but that would have raised the cost, big time. Carpeted stairs are fine for our basement remodel.
Really amazing how much warmer our basement is with these improvements. There are no heat runs in the basement but it is just as warm as the rest of the house.
In one of the pictures below you see all the crap back on the shelving unit. I made the base for two shelves but reused the plywood from the old shelves. I needed to stop the project and needed a place to put all that crap. I will be finishing that shelving area with plywood shelves, a wood panel against the insulation and stud wall at the back and to make the shelves look thicker, false fronts for each shelf.
