An industry leader said the trade was in its worst state in years.
The construction industry on the Western Isles is in crisis according to the majority of building firms contacted by BBC Alba.
Many firms have shed jobs and expect to have to lose more staff as there was little prospect of any new contracts for the foreseeable future.
John MacIver, a self employed project manager, said the situation was the worst in 30 years.
Problems on the islands reflect difficulties elsewhere in the UK.
Mr MacIver said apprentices would struggle to find alternative work on the isles.
He said traditional industries such as fishing and the production of Harris Tweed were not offering the jobs they have done in the past and there were few opportunities in the new renewable energy sector.
Mr MacIver said: "It's the worst I have seen it for the past 30 years.
"I am not exaggerating. We are going to lose about 80 well trained, well qualified apprentices out of the industry.
"There is not much other work for them here."