How To For Those Looking for Tips on Carpet Install

I did my carpet about 18 years ago. I originally trimmed the edges at the door and folded it over the pinch weld seam, my sill plates split after time, I don't know if it was because of the carpet being folded over the seam, so I am going to trim it level with the pinch weld and maybe stick it down with some double sided duct tape, as soon as I find my heavy duty shears. I bought them at that time. I looked at 4 different stores(hardware stores and a Walmart)and can't find another pair.