I have spent many hours wandering through Construction Junction. It's the type of place that you have to keep coming back to because you never know when you might find some treasure. They specialize in building surplus and reclaimed materials, so they have everything from an entire back wall full of old doors to full kitchens and a dozen toilets in different colors. It's a great place to check out if you are remodeling your house or if you're interested in finding something funky you'd never be able to find anywhere else.
The staff here is also super helpful and there will always be someone around to help you get your new purchase out to your car.
CJ is also home to one of Pittsburgh's recycling drop off centers, so you can come here to sort out your commingled recyclables and then go shopping for a new mantle or some headless manequins. You really never know what you might find.