Time to spruce up the bomb shelter? ;)

You could use the product shown here http://www.bobvila.com/BVTV/HomeAgain/Video-1421-01-0.html glued to the wall/ceiling.

Or

Shoot and glue 1X stock 1/4 or 3/8" wider than the crown you are using, rabbet the excess width so it becomes part of the finished crown. You can then install your crown over that.

good luck

cj

Don't force it, get a bigger hammer

Cletus, you're losing me on this one. What do you mean by making pc. 1/4" to 3/8" wider than crown. Does that pc go on wall and ceiling. I think it's a good idea, but I dont quite know what you are saying. Could you please elaborate?

From the top of my head, on the ground, I would affix the 1x into an inverted "L" w/ brads & glue. The legs would receive the rabbet that forms an additional reveal when the crown is mounted.

The "L" is mounted to the wall with adhesive and concrete fasteners and the crown is mounted to the "L"

Just a thought,

cj

Don't force it, get a bigger hammer

Use a backer, similar to dropping crown for lighting.

Go to the DIY page on http://kingofcrown or the notebook & tutorials at http://altereagle.com and look at the installation tutorials.. specifically on page 2 of the tutorials you'll see how to make a backer to the spring angle of the crown you will be using.

Once you have the backer cut, install it using construction adhesive and tapcon screws.

To install the crown in this situation use finish screws, they will hold the crown the the surface better than shooting nails. You start the install with nails, then go back & snug up any spots that need it with the fin. screws & caulk the top & bot as usual, use the new titebond III glue for the joints.

Make sure you have the crown primed all sides, and I'd prime the backers as well the contact with the concrete may draw moisture & expand / contract more than you would want.

http://www.altereagle.com/

http://decks-ca.com

http://kingofcrown.com

Alter Eagle Construction & Design