Steel Lentil Replacement for Window-to-Door Conversion

Old 02-10-15, 11:44 AM
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Steel Lintel Replacement for Window-to-Door Conversion

Hi all. Working on a project that involves replacing a basement window with a steel door. The construction is brick veneer over 7" concrete block on basement level, with brick veneer over wood frame on second level.

The current window opening is 36" wide, with a steel lintel above it. The rough opening for the new door frame will be 46" wide, so we'll be expanding the opening 10" to the right, and down to the slab (as seen in photo).

The brick and mortar seem to be in good shape. No visible cracks. (What looks like cracks in the pictures is actually dead ivy.)

Our assumptions so far are as follows:

1) The existing lentil will need to be replaced with a new lintel, approximately 58" in length, to span the enlarged opening, +6" on each side. We are spec'ing 4"x3"x1/4" angle iron.

2) We'll have to remove the 2 rows of brick above the opening to get the old lintel out, and the new lentil in.

3) We will start from the inside and first remove the concrete block layer to expose the brick from behind so that we can better see what we're dealing with.


A) Given this is a 2-story brick veneer, and we're removing an extra 10" of brick to the side of the current lintel, how important will it be to provide temporary for the brick while we remove the old lintel and put the new one in place? And what's the best method for that?

B) Is it important that we replace the lintel before removing any of the extra brick below it? I have seen videos (like this one) of cutting doorways in brick veneer without adding in a support, then sticking a lintel in after the entire opening is cut. Is this asking for trouble?

C) I have studied diagrams of proper placement of flashing and weep holes above the lintel. How important are those items in this case?

Anything else I need to be aware of?

Thanks in advance!


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Last edited by diyATL2015; 02-10-15 at 02:02 PM. Reason: spelling
Old 02-10-15, 04:10 PM
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A lot depends on the strength of the existing mortar and whether or not brick ties were used to help keep the veneer stable. Hopefully your mortar is good quality and won't go anywhere. If all goes well you won't need any extra temporary support, which would just be in the way of placing the new lintel ASAP. As far as flashing and weeps, yes you definitely want to install a membrane directly to the clean surface of your sheathing and over the lintel. (remove felt as needed) Then slip a strip of felt under the existing and over the membrane. (lapped shingle style)

Install your new lintel as soon as possible after you have demo'd the smallest possible opening for it, and support the bricks above the lintel with some tight fitting blocks+shims until you can get it bricked back in.
Old 02-10-15, 09:13 PM
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Depending on a lot of variables, you may want to consider increasing the thickness of the steel angle from 1/4" to at least 5/16". Increasing the lintel's span length by 28% (as your plan calls for) results in a 63% increase in bending stress the lintel will be carrying. Using the working stress method, applied bending moments are computed by squaring the respective span lengths. The last thing you want to see is the mortar joints cracking and separating above your newly-installed lintel, which they'll do if the lintel begins to sag appreciably because you over-spanned it.

And please note: You will be using steel angle, not angle iron. The latter hasn't been available in this country for almost a century. If you actually have any, its antique value would be far too valuable to use (or waste, actually) as a structural load-carrying member.

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