Credit: Original article published here.

Here at Wells we receive many different questions about our hollowcore. Below you will find several of our most frequently asked questions. Take a look and see if you can learn something new!

• What is hollowcore?
  • Hollowcore is a prestressed, precast element with formed concrete tubes running the length ways of the piece. Wells hollowcore depths include 8”, 10”, and 12”.
• How is hollowcore made?
  • Hollowcore at Wells concrete is made with an extruder. Concrete is poured in the top of the machine shown below and extruded into the hollowcore planks. Please see page 3 of the hollowcore brochure.

• What are the benefits of hollowcore?
  • Hollowcore has many benefits. Below is a list of just a few.
    • It’s quicker to install than a poured floor.
    • It’s lighter than traditional slabs due to the hollow cores.
    • Hollowcore provides long spans.
    • Using hollowcore allows for more head room from floor to floor.
    • It provides a fire barrier.
    • It helps to reduce noise from floor to floor.
    • Hollowcore is virtually maintenance free.
• Will the hollowcore provide a perfectly smooth surface?
  • The bottom finish on H.C. does have a smooth surface that can be prepped for paint. The top surface is rough enough to accept a structural topping without scarifying. Please see page 3 of the hollowcore brochure.
• What is done to finish hollowcore at the project site?
  • After the hollowcore planks have been erected the joints are grouted solid. This is typically the only thing that needs to be done to finish the plank unless there are special requirements on the job.
• What openings can wells concrete put in the hollowcore?
  • Opening sizes are driven by loads on the plank, how many strand the opening is cutting, where the opening is located on the plan, and what direction the opening is running in relation to the plank. A good rule of thumb is that notched openings should be no wider than 2’-0” into one 4’-0” plank. The length of the notch will depend on the items listed previously in this statement. Wells can also supply a steel header for openings larger than 2’-0”x 2’-0”. These openings should not exceed, but are not limited to, 8’-0” wide running perpendicular to the plank (see snip below and page 25 of the hollowcore brochure.).

• What needs to be done to finish the openings?
  • It all depends on the purpose of the opening. Most are framed out by the trade that needed the opening.
• What needs to be done for openings less than 100 square inches?
  • Openings under 10”x10” are to be cut in the field. These opening should be located to go through one of the hollow cores to avoid cutting the strand. If a strand needs to be cut the opening needs to be ran past our engineer.
• Are narrow width slabs available?
  • Yes narrow widths are available. Our partial plank are cut in the yard and can accommodate many different widths. Please reference page 8 of our hollowcore brochure.
• Will the hollowcore cover the entire floor area?
  • Yes, it certainly can!
• How is the hollowcore erected?
  • Plank is erected using steel cables and nylon straps. Wells also installs steel cable lift loops in plank that will be set in tight places.
• How is the hollowcore connected to my building?
  • There are many different ways that plank can be attached to a building. Please see page 22 of our hollowcore brochure.

Nate Roscovius
Project Manager