Silpoly 20Dx50D floor material?

"These pinholes were made by some very small sharp things – I'm guessing needles that had broken off of a pine cone. The bottom of my sleeping pad is already 50D, so would the Tyvek have helped?"

I generally do a bit of gardening before I pitch camp, running my hands over the ground where my pad will be. Being made of multiple layers of fibres, I do think Tyvek is more puncture resistant than woven nylon though.

"A 30D floor + section of 1/8'' foam would probably weigh similar to a full Tyvek floor."

Well, people here are talking about weights of around 1.5-1.6oz/sq yd for sufficiently waterproof nylon. So for a 3yd floor, that's 0.6-0.9oz lighter than the Tyvek alternative. How big a piece of 1/8" foam weighs 0.9oz?

Cut out the floor last night and weighed it. Kyle, I must have gotten a little extra, as I now get 1.44-1.45 oz/sq-yd, which I think is pretty good.

I did not realize 1.8 oz/sq-yd was the weight for Tyvek housewrap – I assumed that was the weight for the soft structure Tyvek. I'll agree that Tyvek housewrap would provide good puncture resistance, and that the weight is not bad especially given how heavy 30D silnylon has gotten lately (ZPacks lists its Tyvek weight at 1.85 oz/sq-yd though). Still, I have a 35'' x 19'' wide piece of 1/8'' foam that weighs 1.4 oz, which I will choose instead