When I was working for them they were excellent. Good backup, paid on time. I was taken on full time by School they sent me to
Cons
Wanted to get back on their books, nightmare. From what I could make out they judged the time I was working for them as a break in employment and they could not give a reference and they would not accept a character reference from the school I was at Don't ask me I never got it. It cannot have been my references as I got taken on by another academy trust using same references. Beyond me
TIB provide great work opportunities in school caretaker roles. They ensure the relevant training in the required H&S modules is provided up front and if you have some DIY skills you are ready to go on your work assignments. This can lead to full time positions if that is what you want. My experience has been very positive on all fronts as the work environment is positive and rewarding.
Cons
Some work opportunities (though not all) may require an early start or alternatively a late finish but if you flexible this can be an advantage.