TJ22

My basement window is sitting on 10" concrete block. On top of the wind is a 2by treated sill plate. On top of the sill plate are 2 floor joists and there is some slight deflection in the sill plate. The joists are cantilevered to the deck. However there is nothing but the sill plate holding up the joists. The exterior cantilevered deck joists appears that they may be sitting on steel angle but its just the angle that is used to support the brick facade, I dont believe it is there to bare load. Its not a lintil that would also support the sill plate.

I had a structural engineer in to look at it, in addition to other issues and he suggested bolting steel angle to the block. I did some quick reading and to get any type of support from that proposed solution, the angle would need to be rather large and make the window in operable.

Any ideas?

nealtw

Welcome to the site.
Did he not requimened a size to install?
What did he say about the angle iron outside? And how is it attached to what and has it got a bend to it?
You said the joists outside were cantilevered, so they have no other support like a post under the other end?
A cantilevered joist would be an inside joist that continues outside for one third of it's length with out other support.
Is there window above this window? If there is a window above that is the same size or bigger, the header above that window will carry the weight above and you only have to worry about the weight of the floor.

BridgeMan

Your engineer dropped the ball by not coming up with the appropriate steel section (angle, channel, I-beam, or other) size needed to support the loads applied from above. If we knew more about the window limitations and geometry involved, we might be able to offer some meaningful suggestions.

For sure, whatever you come up with for a strengthening member, you would to well to (gradually) raise the sagging joists and sill to eliminate the sag before bolting the new member into place. A few adjustable jack-posts would work just fine. And make a point of not damaging the integrity of the sill with your connections--meaning fabricating some short "wings" that extend horizontally from the backside of the new member onto the top of the sill, such than your attachment bolts won't split the sill.

A few more thoughts--if there's a deck outside, why would you need to have a window that opens? Also, there's also a good chance that the cantilevered floor joists are carrying some load from a deck ledger outside. Meaning you certainly don't want to skimp on the strength of the sill reinforcement member.

Wuzzat?

If the window upper horizontal member is not bent down slightly (stretch a line to check) then the window is carrying no load. In this case the member acts as a strain gage.

TJ22

I am attaching 2 photos. I think the window is about 30" wide.

nealtw

If you are asking what's wrong, the simple answer is "everything".
You might look at lowering the window and putting a header under the joists. If the framing beside the window on the inside is 2x4 going down to foundation wall you might get away with hangers for the header.

TJ22

Appreciate the feedback, and I am aware "everything" is wrong. Really just looking for suggestions on what I can do to fix it. I thought about pulling the window and installing something smaller with better framing, and a host of other ideas, none of which is ideal. I was hoping to find a simpler solution, but I was unaware that the strength of steel angle at least what would fit and leave the window functional, is not that strong.

I just realized from the photo you cannot tell but the deck does have supports (4x4 posts) outside at the end and is not a true cantilevered deck.

BridgeMan

Replacing the window with a shallower unit is probably your best option, allowing you to install a decent (4 x 4?) header above it, and under the existing sill plate. You could slowly jack the header into position with a small hydraulic jack, taking the "whoops" out of the sill plate. I think a slider window would be the way to go, in terms of reasonable cost, ability to open for ventilation when needed, and not looking awkward.

Wuzzat?

Does your present setup cause any problems?

TJ22

The present setup doesn't cause any noticeable issues. It has deflected slightly but its only noticeable if you put a straight end on it. I am more concerned for the future and since I was tackling some other issues, I figured I would address it. A smaller window with a double 2x4 header, with proper framing seems like the proper solution.