The Poly Dome Floor Inserts are an economical way to form holes in concrete floors and leave a ledge around the top to put a 1/2" thick cover in when finishing the builiding. This system is fast and easy to install. There are several different different depths that can be used. 5" and 7.5" are the most common, others can be done.
Once you have the 5" deep insert in its proper location simply screw it down to the form with 4 screws. If you use the 8" deep insert you just use longer screws and go through both the insert and the lower extension. Once you have the inserts fastened down just install the top cover and you are ready to pour the cement. The cover does two things, it helps to keep the insert round while you are pouring the concrete and keeps excess concrete from going in and filling up the insert. Making clean up easier. When you go to remove the lower support, just remove the cover with a screw driver, take out the 4 screws, replace the cover and you are done.
When you need to seal the floor you just remove the cover, install the 2.5" tall extension, lay a bead of silicone around the base of the extension to seal the extension to the insert. Now you can seal the floor and the sealer will not run down to the floor below. This saves time and labor on clean up. When you are ready, just lift the extension ring from the insert, brush off the silicone and you are ready to use the ring on the next floor.
Here is a section of floor that has the 5" tall inserts with the covers on. Here they used a waffle forms about the size as the floor insert, and set the rebar around them.
Once the floor is poured and you are ready to take the waffle forms down, just pop the cover up with a screw driver and remove the 4 screws you installed to hold the insert in place. You can put the cover back in place or use a steel plate during construction.
The real advantage to this system is the ease of setup and installing the inserts. They way the top of the insert is recessed 1/2" to allow the cover to set flush with the floor. There is also a 3" collar that sets in the recessed area at the top of the insert that can be used so the floor sealer does not leak through to the floor below. There is also a 2.5" extension that can be added to the bottom of the insert for an 7.5 " thick floor.
Here is a close up of an insert that is screwed in place with the cover removed. You can see one of the 4 tabs used to hold the insert in place.
Once the waffle forms are in place you can mark the location where the inserts will go, line up the tabs accordingly and screw them in place.
This system is easy to setup and is much faster and
cleaner that drilling the hole after the floor is poured. The plastic
insert stays in the floor so you always have a clean finished looking
U.S. Patent 6,088,972
U.S. Patent 6,088,972