Epoxy Coating Floor - Expansion Joint Qs

[rockyballbuster]

I'm getting ready to laydown some PSX700 epoxy flooring. All the prep work is done (dang!). I reviewed the posts on PSX700 (e.g. Scrambler's thread) and have decided to use it.

The Q I have is on the expansion joints. I'd like to fill them in with caulk and have a seamless floor. However, I've heard from a local "expert" that the joints will eventually crack with time. He recommended leaving it open. But the whole reason I'm epoxy coating my floor is to have a surface that I can wash and squeegy out.

Anybody have any experience filling in expansion joints prior to epoxy coating?

Second question, do I need to cut and pre-fill minor cracks in the floor? I can get a credit card in part of one. Should I caulk them?

BTW, I had a contractor offer to coat my floor for $5+/s.f., but he wouldn't tell me the product he was going to use... claimed he didn't want others to find out because he didn't have exclusive rights on it's use in this area. Obviously, he didn't get the job...

Thanks in advance

 

[Edger]

Expansion joints expand and contract, sometimes quite a lot. Sika recommend for their 11FC that you fill them so that the material is twice as wide as it is deep so when your floor cools down and contracts the product will stretch.

Sun causes the most expansion so If your garage floor sees none or little sun there will not be much movement. I reckon it is better to fill them and if they hairline crack later it will not matter much. Caulk the hairline cracks too even if they move, it should not be by much although a credit card gap is probably a crack right through the slab. I wonder if you had water underneath sometime?

 

[rockyballbuster]

Edger, thanks for the input. No water, real dry here. The slab is newer, about 1.5 yrs old. I'll give it a shot.