lintel retrofi

huangyhg

lintel retrofit
i have a small retrofit project.  i have been hired to work on a small reno project on an existing building.  my end of the project is designing a lintel to support a new wider opening in a cmu wall.  the existing door will be removed and the opening will be widened to approx 10 feet.
anyway, i planned on using steel angles (one on each side of the wall) to support this new opening but they are looking for other options.  i have only worked on a couple of other retrofits before and was wondering if there was an "industry standard" for this situation or if its usually just up to the designer?
thanks
we've done what you have mentioned, used a single angle on each side, but we weld a plate joining the two angles once the opening is made.
how do others do it?
rc
all that is necessary for the triumph of evil is that good men do nothing.
    edmund burke

we typically provide wf shapes with a btm plate.
i use a lot of tube shapes, inset into the opening, a vertical channel afterset bolted to the backside, or a channel, legs up and extended into the extremeties of the opening at either side of the opening.  depends what the owner/architect can tolerate aqs to what i use.
mike mccann
mmc engineering
use a single wf shape at the center of the wall with posts at either end.
i usually use two angles, with the horizontal legs pointed toward each other.  this way, no shoring of the wall is required.  you cut a horizontal slot in one side of the wall, and install one angle.  then you cut a slot in the other side of the wall and install the other angle.  then you remove the masonry below the angles.  finally, you weld a plate to the bottom of the angles to finish off the opening.
the angles bear 8" onto solid masonry at each jamb, of course.
daveatkins
this side of the pond they would install one or two precast concrete lintels.
i agree with the ease of the double angles as i have specified it before but if they want a plain rendered look then precast concrete gives a better finish.