Builder wants me to pay whole amount but work far from complete

[33goingon64]

Build started mid May. Not a huge job:
taking down conservatory
Foundations
Kitchen extension
Some internal alterations to 1 room
Kitchen installation (by a third party but they need to work around them)
Finish, decorate

They are still at stage of finishing external roof on extension, so still got tons to do. Not even done first fix. I think it will be easily 8 weeks more given the speed they work.

He didn't give me a time estimate at the start - we've used him before and he does a good job so we trust him even if we know he's not the fastest.

I paid a deposit upfront and have been paying a chunk weekly since mid May.

We are now 5.5 months on, I've paid him 82% of the total cost. I pointed this out today and basically asked if I should stop paying until they've caught up a bit and he said no, it's best to keep on paying. When I pointed out that there's only about 4 weeks left til I'll have paid the whole amount he said it's normal nowadays to pay up before the job is finished.

I think this is unreasonable and am planning to withhold further payments (or at best reduce them significantly) until some more jobs are ticked off.

What do you all think?

This all this. His progress sounds painfully slow and l wouldn’t give him anymore money

Definitely no til June b is done to your complete satisfaction. Full stop. He is trying his luck!

100% no way should you pay. I would never pay full amount until job is done and that includes all tidying up afterwards. Learned our lessons in the past!

I paid a deposit upfront and have been paying a chunk weekly since mid May.
And you'll end up paying weekly long after you've passed 100% of the original quote. It's always better to pay by stage achieved, not time spent. And that way you can see where you are in terms of over-/under-budget at each stage.

he said it's normal nowadays to pay up before the job is finished
If you've already paid over 80% of the quote, you should have long since covered the costs and are now paying his profit. Stop.

What does your contract say?

We paid 50% on day 1 (no deposit) a further 40% when basically finished apart from snagging issues and the final 10% when totally finished and signed off.