Basement window retrofit - Code Qs

[Greg]

I'm going to add a egress window to a room in the basement so that it can be used as a means of escape in the event of fire. Since this is a retrofit, I will need to cut the foundation for the 48x48 window. Code requires the window be not more than 44" from the floor.

If I cut all the way up to the rim joist, I will need to put an I-beam across the span to support the joists. What does code require on the size of the beam that would span 48-56"? If I don't have to cut all the way up to the rim joist, how much foundation above the window must remain before I will need to reinforce the span?

Thanks for your help.

Greg

[Goedjn]

1: I think the window that you are contemplating is bigger than you strictly need. A 31.5" wide rough opening should be more than adequate. On the other hand, if you're going that far, it's not all that much of a leap to just cut all the way down to the floor, and put in a door and a stairwell. 2: You probably don't need an I-beam. You should only need an I-beam if there's something significant, like a post, coming down on that section of wall. If there's any sign of extra blocking in there already, then it's time to panic, and call a professional.

Otherwise, if the wall in question is parallel to the existing joists, just sister two treated joists to the existing rim-board.

If the wall is perpendicular to the joists, pick a different wall, or take enough headroom to put lintel across under the rim-joist.

(Or: Prop up the joists-to-be-undermined with a timberjack and a 4x4. Cut 32" off the ends to give yourself room to work, sister that section of rim-joist as before, and then sister the cut-off joists on both sides, attaching them to the new triple-header with 4.5" hangers.)

--Goedjn

[tbasc]

In addition to Goedjn's excellent advice, a window well used for emergency escape should have - according to IRC - 9 square feet of area with a minimum dimension of 36 inches. TB