I think Glade A is another English term that has slipped into Thai usage along with Plomotion and Galantee. As far as Glade I mean grade A is concerned if his English was sufficient you could ask him as opposed to what? As you say, is there a B or C? I was told my car insurance was Grade A by the sales girl, I thought that meant comprehensive but it doesn't cover theft... Okay not a builder but an example of a good sounding sales pitch that doesn't really do what it says on the tin.

There is certainly Grade A, B etc. in many building materials in Thailand westerby.
Cement for 1 - I believe different Grades for different jobs.
Tiles, yes Grade A should be perfect, Grade B are seconds, some can be OK, some not..

From memory http://www.coolthaihouse.com/ discusses the cement thing in some detail.

The important thing is that if you are paying for Grade A you actually et Grade A....

i bought 90% of my material from globel house all item's are priced as for cement stay well away from red lion brand you may as well use dung and straw.
ps is his uh and has a head like stewie from family guy if so walk away now,i am speaking from hand experance.

everything from the inexpensive cinder blocks and up, especially cement have different levels of quality, and definitely makes a difference. the blocks were a mere 50 satang difference, but well worth it, cement at the time, was up to 50 % difference, but again, depending what using for, well worth it.

also watch you electrical wiring, a major difference for different uses, many use 1 x 1.5 for everything, or something like that. water heaters and heavy draw appliances will need much more.

been there and replaced/upgraded too many things. take care and lots of research, you'll need to complete educate yourself, or get a excellent reference with many kudos for the same from different people. good luck.

That will be 1 x 1.5sqmm for all lighting and 1 x 2.5 sqmm for GPO, general power outlet, and 4mm for hot water heater , stoves.

Add the preferred 4sqmm for the earth / ground wire, which is always green

GPO should be 3 pin, and as a preference all my GPOs have a switch to turn each GPO outlet off independently