Hi: I've actual had a DOT engineer ask me to supply a 1/2" riser for use in a repaving project on some sanitary manholes. I had to explain that they were not available in this thickness. But after the paving was completed, they said that because we wouldn't provide risers, they were ordering that we reset the manhole covers to match grade. The covers were 1/4 to 3/4" low. This lead me to do some research and I found this website: tophatrisers.com. I am still trying to get approval to use them, but, they are reasonably priced and seem to be well secured to the manhole cover. See what you think. BC
