# Basement Finish - Soffit Against Poured Concrete



## InDashMP3 (Apr 9, 2012)

I'm looking to start finishing my basement, and have a likely common scenario, but I'm not too sure how to proceed. The basement walls have plastic lined insulation fastened to the concrete walls. My intent was to frame around the wall out from the insulation. On one angle of the wall, I have an HVAC duct that runs up against the wall. Because I wanted to run my studs out from the insulation, I'm not sure how to frame in a soffit where the HVAC duct is. Is it O.K. to fasten a 2x2 directly over the insulation? How do I frame that wall? What will my top plate fasten to since the duct work is directly overhead?? Many many thanks!


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## cortell (Nov 27, 2010)

I'm not sure I understand the question correctly. Can you post various pictures of the area?


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## InDashMP3 (Apr 9, 2012)

Hope these help!


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## cortell (Nov 27, 2010)

Ahhhh. MUCH better. 

I would build a bulkhead. Now, if anything along that stretch has access requirements (e.g., an electrical box, or a gar or water line valve), you'll need to include an access door.

However, the solution is tricky in this case because you have hardly any access to the floor joists along that foundation wall on the right (the second pic). What I would do is not enclose that narrow strip under the vent. That is, I'd stop the framed wall short of the beam and frame down the length of it. Use that long stretch of unfinished basement for storage. 

Now, if you want to replace the existing insulation along that foundation wall, that's a different story... It's all a matter of how much you want to grow your project  Given all the utility work running down that area, though, I _really_ recommend leaving that open.


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## InDashMP3 (Apr 9, 2012)

cortell, thank you very much for the reply. Hmm...I hadn't considered leaving it open. It certainly would make it much easier! Ooops!! As I type this, take a look at the additional challenge though..see the two columns? The bathroom is supposed to go in there. Notice the floor shower rough in, and toilet rough in.. I've attached a little rendering of the "plan" in that area. I've filled in with RED stars the two columns you can see in the picture, and placed a black line to represent the beam.


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## cortell (Nov 27, 2010)

Wow. You certainly have a plan! 

OK, well I don't really see many options here. First, I think that insulation will have to go. Replace it with foam board. Next, fasten a 2x4 ledger along the length of the wall to frame a bulkhead. In fact, I'm foreseeing two bulkheads: one that wraps the I-beam; the other that encloses that area under the duct. If you make it one big bulkhead, it would leave you with a pretty low ceiling over the tub. You'd have to measure it out to see if it would work. Or you could leave the I-beam exposed and just do the one bulkhead. Depends how much you like having an I-beam running through your bathroom. Now frame the wall under the bulkhead. Refer to the following link for guidance on framing and insulating walls in a basement.

http://www.homeconstructionimprovement.com/how-to-insulate-basement-walls/

Bottom line, that insulation has got to go, if you ask me. I'd replace it everywhere, not on just that one wall. 

Again, DO NOT close up anything that is meant to be accessible. Clean out, electrical boxes, valves, etc. You'll have to build in access panels if you have any of these things.

Also, I would make sure that vent has no leaks. Seal it up tight before you close it up


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## InDashMP3 (Apr 9, 2012)

awesome. Thank you very much for the great info. I had not yet stumbled upon that link you provided (It's a good one!). I think I will be pricing the foam board insulation tomorrow. I'll "at least" replace it all on that wall.

Thanks again!


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## cortell (Nov 27, 2010)

Sure thing. Good luck and please keep us updated.

BTW, that duct there is probably going to save you a ton of hassle and money since it spans both rooms. That said, there's the question of how tapping into it will affect flow to the rest of the house. Only a licensed HVAC contractor can assess that for you. Also, you may already have thought this through, but you need to consider how you're going to vent the bathroom (to the outside), vent the plumbing, ensure you have an egress exit, etc. Basement remodels involve so many little things that usually add up to big things. Making sure you get permits for every aspect of the remodel (plumbing, electrical, HVAC, structural) is the best way to ensure you end up doing things safely and to code.


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## InDashMP3 (Apr 9, 2012)

cortell,

Thanks again for the informative help. I will indeed solicit the assistance as needed, as well as work with our county inspectors. 

I have attached a rough markup of the design. Assuming the white insulation will be taken down, I will install some foam board in it's place. Would I then anchor the wall edge of the bulkhead 2x2 directly over the board?


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## Evstarr (Nov 15, 2011)

Don't use 2x2 framing. Use pt 2x4 and mold resistant drywall. When you take that insulation down, make sure it isn't at all wet behind there. If it is tend to the water before you proceed.


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## InDashMP3 (Apr 9, 2012)

evstarr - thanks. I actually only mentioned the 2x2 in regards to the (ledger?) that will make up the concrete wall side of the bulkhead - the horizontal line indicated with the red arrow. Actually, I am a bit confused about that part. Not sure what the studs will attach to if the pseudo top plate is only 2x2! Also, do I attach that directly over the foam board (compressing it?) I plan to do all the studs/plates in 2x4, with pressure treated lumber on all concrete touching surfaces.


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## cortell (Nov 27, 2010)

InDashMP3 said:


> cortell,
> 
> Thanks again for the informative help. I will indeed solicit the assistance as needed, as well as work with our county inspectors.
> 
> I have attached a rough markup of the design. Assuming the white insulation will be taken down, I will install some foam board in it's place. Would I then anchor the wall edge of the bulkhead 2x2 directly over the board?


Nice markup. That's the "one big bulkhead approach". It's certainly the cleanest way to close up that area. Again, though, make sure you don't end up with insufficient clearance over the tub. I'm 6'3" so that would be a major concern for me  The concern is even higher if you were planning on putting a light over the tub.

As for ledger over foam board...honestly, I would check with the foam manufacturer. Give them a call and see what they think. My instinct would be to install it over the foam, but not overtighten the connection. It should be nice and tight, and that's it. The reason I think that would be acceptable is that we're not talking about a significant load. We're talking about a relatively narrow run of sheetrock, and that ledger is sharing half the load. I'd make sure I used a deep enough anchor. But, honestly, I would check with the foam manufacturer first. If they say no go, then you just need to attach the ledger straight to the foundation and split up the foam. Make sure you use PT lumber in that case. 

I also agree on not using 2x2; use 2x4.


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## cortell (Nov 27, 2010)

InDashMP3 said:


> Not sure what the studs will attach to if the pseudo top plate is only 2x2!


That's not any sort of top plate The short runs of 2x4 from the ledger to the other corner of the bulkhead will be what you'll be fasten your top plate to.


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## InDashMP3 (Apr 9, 2012)

Take a look at this picture. It shows the ledger as a 2x4 secured over the foam board and into the wall. The problem with that, is when I lay out my 2x4 studs, they will only have half the surface area to attach to since the ledger (top plate) is mounted to the wall. Shown by the arrow. Do I mount another 2x4 on top of the ledger??


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## cortell (Nov 27, 2010)

Your picture lacks 2x4s running from the ledger to the left corner of the bulkhead. Those provide a nailing surface for the top plate of your wall. Your top plate will not be nailed to the ledger,


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## InDashMP3 (Apr 9, 2012)

cortell said:


> Your picture lacks 2x4s running from the ledger to the left corner of the bulkhead. Those provide a nailing surface for the top plate of your wall. Your top plate will not be nailed to the ledger,


OH YEAH!! I knew that!!! :whistling2: :laughing:

haha.. thanks.. what was I thinking!!!!????


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## cortell (Nov 27, 2010)

This made me realize that the ledger has further responsibility beyond holding up half the weight of the narrow strip of sheetrock and cross studs. It also needs to keep the studded wall in place. This would lean me away from studding over the foam board. I'd want a pretty tight anchor connection, and I suspect that would not be good for the foam board. But I'd check with the manufacturer all the same.


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