Foamboard cornice

Shelly Szpara
by Shelly Szpara
How can I make a foam board cornice for a wide window? I need to join more than one piece of foam core and I don't know how to do that.
  6 answers
  • Jeanine Jeanine on Jan 01, 2015
    Toothpicks...push toothpick half way in on one foam board evenly spaced then slide the other board into the toothpicks sticking out.
  • Shelly Szpara Shelly Szpara on Jan 01, 2015
    Thank you so much. What a great idea.
  • Michela Shoemaker Michela Shoemaker on Jan 01, 2015
    I took an extra smaller piece of foam board and applied on the back where they joined. When you cover the cornice you won't be able to tell. Don't forget you will need an additional support for the cornice if it's too wide.
  • Shelly Szpara Shelly Szpara on Jan 01, 2015
    Thank you Michela. A very good idea.
  • Karin From B'ham Karin From B'ham on Jan 01, 2015
    I've made foam core cornices and they are genius. I wouldn't hesitate to duct-tape those suckers together. Stabilizing with another piece of foam core behind where the pieces meet would be a good idea. Once you add batting a fabric, no one will know. Good luck!!
  • Karen Young Karen Young on Jan 01, 2015
    Rigid foam board insulation comes in 8 ft length. If you need longer than that, I have used both the toothpick with glue and attaching an additional piece behind to join pieces. Both held up.