Hello to all - - - -

I have a concrete block house with 8 foot sliding doors leading onto my back porch. I have gotten an excellent price ( for FREE ) on a set of 5 foot French Doors and would like to install them in place of the sliders. Any and all advice would be appreciated. I have a decent amount of DIY experience. My thought would be to frame the opening to proper size and probably use wire mesh and plaster on the outer wall to match up to exterior walls and drywall to match interior walls. I'm not sure about the threshold or any details. Like I said - I will definitely appreciate any and all advice : the greater detail - the better. Thanks in advance. BILL

This should be fairly straight forward assuming the height of the new doors also fits. You'll definitely need a strong helper as this is heavy and awkward work.

Are the french doors pre-hung? If so, they will have their own threshold, so you should just take one set of doors out and install another. If not, then you'll spend a half a day making your own. In theory, the old opening should have all the structural stuff taken care of, so there are no requirements for posts/ beams etc. You need to spend more of your effort in insulating, sealing, and weatherproofing.

You may want to look at installing sidelights instead of plastering. Going from 8' to a 5' opening will significantly affect the light and view from your room. Here is a sample for a single door.
http://www.amberwooddoors.com/images/nsled2b.jpg

Thanks for the reply - - - no : they are not pre-hung. I thought about using side-lights - just was trying to keep the expense down. Thanks again.