I'm travelling to Thailand for 7 weeks 6th March I understand I need a visa for over 30 days I will be in Burma for 5 days from 15th March and returning to Thailand will my 60 day single entry tourist visa be not valid when I return

 

Cheers

Whether you need a tourist visa or not for your trip depends upon your nationality. If you are from a country that qualifies for a visa exempt entry you would get a 30 day entry when you enter the country that can be extended for 30 days at immigration.

If not you would need to get a single re-entry permit (1000 baht) to keep the remainder of the 60 day entry from the tourist visa valid when you return from Myanmar (aka Burma). You can apply for it at a immigration office or at either airport in Bangkok on departure from the country.

Your single entry will be used when you enter Thailand but you have permission to stay for 60 days.

 

Obtain a single e-entry permit from your local Immigration office, which will allow you to leave and re-enter keeping your 60 day permission to stay valid.