We have installed a new bathroom sink. Drain from sink is 1.25" diameter. All other piping is PVC and is 1.5" in diameter. Other sinks in house look as if the 1.25" drain is inserted into the 1.5" down piping that connects to the trap. It appears to be watertight and secure. What did they use to make up the space around the smaller pipe to make it fit tight in the larger diameter pipe. Thanks, Mick

I believe you have bought an western standard furniture, it ussually has a 1.25". (eastern standard is 1.5"). You can use a gap filler which you can buy in hardware, then , cover the connection with a cap, which ussually comes free with the bathroom sink or lavatory. No need to woory about that gap, it is not as complicated. It's the normal procedure. Happy remodeling. Have a nice day.

Hi Mick,
Disregard the advice above. That lavatorys 1 1/4" tail piece connects to a 1 1/2" trap raiser through a compression fitting. This compression fitting's 1 1/2" however it has a 1 1/2" X 1 1/4" Nylon gasket that seals the connection. Pick one up at your local plumbing shop. Good luck, Tom