Will they die and just fall over?
yes . PLants need soil and water . cement lack both !
If they were that stupid I'd hope that the workmen would die and fall over. No offense intended.
They will die but not right away. It might take a year or two, depending on their size and age. And they probably won't just fall over. The leaves would die, then the smaller twigs, then the larger twigs, then smaller branches, then larger, etc. It might take several years for the thing to 'fall over.' We have had a large stump in our side yard for about a decade. The tree died about 15 years ago, but the trunk is still there. 'Course, this was a BIG tree-- the trunk is about 3 feet in diameter.
Yes, undoubtedly. The cement will set and restrict the roots. The roots will also be deprived of water. If these are new trees, you need to get them out before the cement sets hard - they might survive if you wash the roots clean with a hose pipe. If they are existing trees, their roots will be deeper and more established so you just need to get the cement off them. Be quick because cement is corrosive. Any hard landscaping around trees needs to porus to allow the water to percolate through to the roots. Good luck - oh, and don't fotget to sack your builders - they're numpties.
