Non completion of project

Mark Barry from The Carport Place attended brief on site to understand project. Committed to 2 week full installation and 50% deposit paid on 12th June. Car port structure took 8 weeks to be erected with limited/no supervision of Owner. Workmanship was below average and had to send on going photos and stay close to achieve satisfactory finish. We eventually proceeded after several repair attempts and further 25% payment was made leaving final 25% after completion. Supplier now wants last payment in advance or will not finish the project. Having to bring in 3rd party installer to complete work after 8 weeks and litigate for damages. Would not recommend supplier.