At one time you could get Styrofoam beams at DIY. Check with companies who make fake trim for your doors and base boards. By the way just don't ask a sales person do you have as most of the time they can't carry all products that a company may have, ask for the address and phone number of the companies and call them ask for there web site. If your local sales person won't help you ask for the manager and tell him what you are looking for. I have found some help on finding some products by going to DIY and other sites and e-mailing them. Do a search, try Styrofoam as your key word.