Use 2x4 pt plates,a rotary hammer/sds bits would work a lot better than the hammer drill,a whole lot better, when drilling the hole dont do it all in one pass back the bit out half way and go in again. Clean the hole out with air before you drive the 1/4'' hex drive tap con. Done corectley there is no need for adhesive. Use 1 5/8'' ss screws. J.

You are putting down shims or furring strips, not joists.

I do not think the 3/4" thickness of PT is going to hold the screw. Ipe likes to move, and it's really strong. The short screws will pull loose from the soft thin PT wood. I have built roof top decks with 2x4 furring strips, and that holds the Ipe just fine, but I use 1 3/4" or 2" screws. You say the step is 6-8" right now. Is that a slope, or are you estimating? A step should be near 6" much less is a trip hazard. So if you have 8" now, you could build a deck with 2x4 furring strips and 3/4" decking, making the step 5 3/4" would be OK. You still need to ensure good ventillation on at least 3 sides for a deck this low, whether it gets lots or rain or just occasional.

Thanks for clarifying firring strips vs joists. I'm estimating the step height..I could probably use 2x4.

There are only two sides of the porch would be open as the other two sides are up against the siding. I had thought of of the lack of ventilation and thus was not going to use T&G, but just regular decking. If the ventilation isn't good, what what can I expect to happen? Can I post pics of my existing porch on this website to give you a better idea what it currently looks like?

Thanks

Hi. You probably haven't thought about this thread for some time but how did it go? I'm considering a very similar process and am curious on what you ended up doing and did it work?