I am building a concrete block wall. What is the best way to put in a door or window?

Question

I am building a concrete block wall. What is the best way to put in a door or window?

Answer 1

Leave out the openings, rather than "put them in". You'll know what size these openings are, so just build up vertically where you want them. You'll need lintels above them to take the weight of any blocks above them/ You don't say if it's cavity wall, load bearing wall or just a dividing wall; so I can't comment on which lintel you would need at this time.

Answer 2

Since it is block, I'm assuming aesthetics are not as important.  So go with the steel lentil above the opening.  The blocks on the sides of the opening support the steel, and the steel supports the block row above.

If you are wanting to go with aesthetics, your local masonry supply store can sell you a single piece concrete lentil, to go above the door.

For size, leave an opening large enough to accommodate your rough in opening for your door frame, with some room to spare on each side for adjustment.  Once the wall and lentil are done, go back and shim in the frame, and attach the frame to the blocks as per the door instructions, (you may need some mechanical fasteners from the frame to the block),  then mortar around the frame to fill the air gaps.  

Be sure the door works, before you mortar in the frame.  

Answer 3

Usually you would frame the opening with wood, form the block around the frame, then knock-out the wood and install the window. Pouring the cells of the block around the window gives you better anchorage.