Creating Walkout Basement - Need Advice

[kwolfe]

I have been considering creating a walkout basement for some time now. My basement is 30' by 37'. I would like to put in two windows and a door in order to provide easy access and additional sunlight. I will try and take some pictures this afternoon, however I attached two drawings that give you an idea of the house layout. The door and windows will be on the side of the house which does not bear the load of the floor joists. The openings would also not be directly underneath the support beam that runs the width of the house. The grade of the house on that side should allow me to have a true walkout (no steps, or bilco needed). Oh yeah, the foundation is poured 10" thick walls, 9' high. The blue marking in the first picture are my proposed door and window sites. The second picture gives you a rough idea of what I will be excavating.

My questions (that I can think of) are the following:
1) Since I am located in PA (where it does freeze), do I need to worry about exposing the side of the foundation to frost?
2) Are there any tricks to cutting ou the openings?
3) What sort of additional support do I need once the openings are cut (headers, side support)?
4) What else am I not thinking of (probably plenty )?

 

[MarkV]

Well I don’t think you need to worry about the frost problem. For a 10” thick wall with rebar you are going to have to have a concrete cutting company come and make the cuts. The cuts will require some specialized equipment that you don’t get at the rental store. There are enough variables that I would not consider doing it with out an engineer involved and if your area requires permits they will require it engineered.

It does look do able and you are lucky to have the 9’ ceiling to make it practical.

MarkV

 

[RobS]

Kevin, I got your PM. You saw my thread on cutting windows in my buddy's basement. His was only 8" thick but that saw should work on 10" as well. Not sure about renting but you could buy the saw and resell when finished. You'll probably eat up the diamond chain completely with all your cutting. He was told he could get about four windows out of one chain.

Frost will be more of a concern for the footer, you might check your codes and measure your depth. Stud and insulate the inside of the walls and you should be good.

Sounds like a fun project, keep us posted.

 

[tlbuser]

I
My questions (that I can think of) are the following:
1) Since I am located in PA (where it does freeze), do I need to worry about exposing the side of the foundation to frost?
2) Are there any tricks to cutting ou the openings?
3) What sort of additional support do I need once the openings are cut (headers, side support)?
4) What else am I not thinking of (probably plenty )?

1) Frost/freezing won't be an issue on the outside. You will want to add paint, siding, brick or stone though ($ -$$$)

2) Yes, you should get a structural engineer to approve it. A concrete chainsaw will do the job. Not sure if you could rent one in your area, if not ($$$)
http://www.icsbestway.com/en/images/ICS_GC_ProductGuide.pdf

3) Again, the structural guy will be the best source for that info.

4) Consider two 5-6 foot french /patio doors instead of the door and window idea. More light and if you ever "split" the area, you'll still have an ingress/egress point with little added expense for the cutting. Add a drain grate between the doors and new patio area, a reasonable source for these is a good pool builder in the area.

 

[LK3054KIOTI]

Kwolf I have a house with a walk out and when they where putting in the footings on the walk out side the had to dig down below the frost line to keep the footing from heaving, if you don't already have this I would check on it. or am I misreading your post, is your basement wall already exposed? and you are just wanting to cut the holes if so have at it as long as the support beam has plenty of support under it not above a window or door

 

[woodlot]

Two people have said that freezing will not be a problem, I don't undersstand that. If you excavate one side of your home to create the walkout, I'd think you'd end up with a footing on grade. I'm no engineer, but I'd think that'd be a less than ideal situation.

 

[tlbuser]

Two people have said that freezing will not be a problem, I don't undersstand that. If you excavate one side of your home to create the walkout, I'd think you'd end up with a footing on grade. I'm no engineer, but I'd think that'd be a less than ideal situation.

I based my answer on the assumption that the walls are poured on top of the footers, assumption being that the poured walls were for the basement and that any excavation won't affect the footers and assumption was made that footers are 24 - 36" (or area code) below the lowest point of the wall. Another reason to consult a SE/PE. And no, there should not be any problems on the exterior except for appearances sake. BUT, this exposes another portion of the whole house to the elements and will probably have a negative effect (albeit small, dependent upon direction of exposure to the sun) on the total heating/cooling load for the house.

 

[dtd24]

You will definitely have to worry about frost. If you dig that out you will expose your footing. If I were you, I would pour a 4' wall under whatever I took out. We usually use a 2x8 wall in our walkouts with double 2x10 headers over each window or door opening. Rent a cut off saw to do the cutouts. on the exterior you can pin furring strips to the foundation and side with whatever your building is currently.

Permit = raise in taxes

 

[kwolfe]

You will definitely have to worry about frost. If you dig that out you will expose your footing. If I were you, I would pour a 4' wall under whatever I took out. We usually use a 2x8 wall in our walkouts with double 2x10 headers over each window or door opening. Rent a cut off saw to do the cutouts.

I would be exposing the side of the foundation to just above the level of the basement floor. The basement walls are poured on top of footings correct? Also, are you saying to extend the footer by 4' under any opening I cut?

I plan on over framing whatever opening I make. I figure with 10" thick walls, I would make the header and vertical supports the same thickness. Probably overengineering it, but that cannot be a bad thing.

 

[Builder]

If I understand you correctly and you fully expose your basement walls outside by digging out all the soil to the same level as the inside floor, then yes, you will then have a frost issue.

What you need to know is what the code minimum is for footing depth in your area, then you can underpin your wall to the correct depth. I'm underpinning a garage as we speak in this thread:

http://www.tractorbynet.com/forums/projects/103038-old-world-craftsmanship-how-not.html

If your joist tips are over the doorway you want to cut, one way you can support the opening is by installing a header just inside the doorway. You can saw cut 2 holes in the floor where your lally column poles that support the header will go on each side of your opening. You make the holes 2' x 2' x 3' deep and fill them with concrete. Once the concrete dries, the lally column poles can sit on their new footings. Then you can get a piece a C channel (rated for the load over the opening) and bolt it to the lally column poles (just like the lally column poles you see in the middle of a basement to support your joists. Then, if there's a piece of concrete header from the outside wall still remaining, you weld a 4" angle iron to the back side of the C-channel. This will sit under the remaining concrete up above and hold it from cracking & falling down.

You'll ned to get a sketch & small set of plans together. Call a local PE and ask him for assistance. Or I can give you a name you can call. He'll do some plans for you for pretty cheap.