Hm, woops. My guess that they wouldn't be lossy was based on the
assumption that they don't contain much water. In light of what George
has said, I retract my guess. Putting your antenna close to anything
containing water is bad news from a loss standpoint, as George says.

Roy Lewallen, W7EL

Crazy George wrote:
Ken:

I've not run HF measurements on bricks, but I can tell you that a brick wall
is extremely lossy at 1 GHz and above, by measurement. Their water
(dielectric constant = 80) content is relatively high unless recently baked
and sealed, and depending on the particular clay they were fired from, they
are somewhat conductive. So, placing your antenna close is like putting it
next to a high dielectric RF absorber. Not a good choice.

--
Crazy George