There are several ways to go about building a dance floor at home:
Shower Pan Liner (Easiest Option)
For around $40 you can buy shower pan liner (Gray or Black) from Home Depot or Lowes. You can either buy a big square piece in a package or you can buy it off of a roll:
http://www.lowes.com/pd_20088-138-41630L___?productId=4755182&pl=1&Ntt=shower+pan+liner
This is a good option if you have an appropriate subfloor. However, if the subfloor is concrete or other hard floors like tile it has no flex/spring and can cause injury. Also if you are doing more advanced movements there is a chance that you might poke a hole through the floor with the sharp edge of the hard shoe.
Practice Pad (Portable Hard Shoe option)
This is a patented roll out mat that is great for practicing hard shoe and drilling. The Practice Pad has a specially designed SprungTECH foam layer to give the feel of a sprung floor and help combat hard surfaces. It also has a Grid can be used as a visual aid by dancers of all ages, from beginner to championship level, to self correct alignment, turn out, cross, control and placement. Not a big mat, but great for drilling and beginners!
https://www.irishdancepro.com/
Jubilee Dance Floor (Very Portable)
Individual 2' x 2' sprung, lightweight, interconnecting tiles. This is a more expensive option depending on how many tiles you buy. https://www.jubileedancefloor.com/
Harlequin Dance Floor (Most Professional & Durable)
Harlequin sells floors to dance studios but also has a few at home options. For their complete line of at home practice floors see below: http://www.harlequinfloors.com/us/en/files/pdf/HomeStudioBrochureOnline.pdf Wood Floor (Most Popular, Very Durable) This is the most popular type of dance floor for at home practice but it is the least portable and requires some labor. This is a DIY custom built floor made of plywood sheets and 2”x4” found at your local hardware store. You can make it any size you want and is typically placed in an unused garage or basement. Once the plywood sheets are screwed into the 2”x4” frame you can used duct tape or gaffers tape to cover the seams. Here is an example of a structural layout:
https://s-media-cache-ak0.pinimg.com/736x/5a/0e/5a/5a0e5af2fc2444f6c46a469ae781c196.jpg
If the wood is too loud you can cover it with Shower Pan Liner or other vinyl coverings bought from professional floor companies. The vinyl material is often called “Marley”, which was a poplar flooring manufacturer that is now out of business.