Is flashing required to attach a landing to the exterior of a house
Typically, concrete steps are set onto a slab and not physically attached to the building. There should be about a quarter to half inch gap between the step unit and house. In most installs, a piece to flashing or ice &amp; water shield is placed under the threshold down to the foundation, then covered with a 3/4" trim board. This protects the house from water invasion and also gives a nice look, as the trim can be painted to match the siding etc. The steps are then rested near the trim board. I use pressure treated lumber for the trim board. If you put the steps hard up against the trim or house, expect rot in a few years if it is not pressure treated.