Hi Ryan,
If tax is deducted on the payments through the construction industry scheme, you would not pay tax on the income a second time.
If you are treating this as income, you will have class 1 NIC to deduct or if you class as self employment income, class 2 and class 4 NIC through self assessment.
You may wish to consider the IR35 rules, as you may be affected by them.
Understanding off-payroll working (IR35).
Thank you.