cutting a hole in an existing concrete wall

[dykesconst]

I have a house in Southern California that I was the contractor of record in 2000. I would like to saw cut a 4' wide x 30" opening to install a window. The wall in question is a concrete-reinforced basement wall. It is 9' tall, 12' long before it turns the corner. It supports 2 floors above. Edge of opening is 3' from outside corner, 2' from top and 4'-6' off slab. The ground level outside would be halfway up the window- house is at the top of a hill (no load bearing issues with the soil). Rebar is #5, 2' o.c. horiz. and vert.

do you see any problems?

thanks,

Mike

 

[concretemasonry]

Since you are in SoCal, you may need a permit and sign-off by an registered engineer, especially because of the seismic conditions and variability of terrain.

A 4' wide chunk of concrete out of a basement wall can have big effects, especially is was built according to standards codes (the least you have to do and still be legal) at the time of construction and possibly not today's conditions.

Since you have a basement, you are not in the "flat lands" of the valleys and you probably have some other soil and drainage conditions that require a closer look in addition to seismic.

Even Northridge is generally flat and look at the problems that were cause a few years ago.

 

[jike]

To me a big issue is to prevent saw runby which may cause a crack to go diagonally off the corner of the opening. I prefer to core drill the corners and run the sawcut into them.

 

[cvg]

A steel frame can (should) be installed in the opening to transfer loads and to protect your window.