Andy Eade's Rotten Basement Conversion Thread

Thanks Steve for the drawing and setting my mind at ease. I think Shar is right for me to at least be cautious; particularly as I was talking about maybe supporting a new ceiling on these walls which really would be a lot of extra weight. Now I just have to think about the booming at the perimiter and whether that is signficant enough a factor. I was down in there earlier stomping around again and thinking that surely if the pipe is buried under 2 1/2 inches of cement and 3 1/2 inches of stone that it should really be much more of a flanking path than the slab already is? Also Steve did you get a chance to think about that mystery 2x6 in the picture back on the last page? Did the pic make a little more sense with the labels? Let me know if you have any questions about it or need any more info. And as always, many thanks for your valued input. Andy

also, in addition to my question above; one more beef-up question. If the subfloor above has a few knot-holes here and there should I fill them with mud before adding the Rock? Thanks, Andy

Yes... Or acoustic sealant.

knightfly wrote:

If you use a wider plate for the wall frame, and use sill seal under it as I drew, you will have plenty of support for a 2-layer gyp wall. We're talking about 50 pounds per linear foot of 7 foot tall wall here, spread out over 7.25 inches wide, for a load of around half a pound per square inch...

I don't want to quibble but the way steve's sketch is drawn will result in an uneven dispersion of the weight thru the 2x8 to the concrete below. If you're gonna do it that way at least center the plate on the 2x4 wall so it is loaded equally. I wouldn't do it that way if it were me. I don't think the river rock keyed arch analogy will "hold up" to serious scrutiny- unless there is a foundation below the river rock, it will just be compressed into the soil below, especially if the layer of concrete topping is not tied into the existing slab. The pipe, if it is DWV with holes, will certainly deform under load. While steve's right about it not being that much weight, still one can expect some settlement over time, especially with constant vibration. Think about it - the 2 1/2" thick layer of concrete will function as a beam running the full length of the wall, only it isn't reinforced to take tension loads (concrete is very strong in compression, but worthless in tension) nor is it attached firmly on the ends or sides (I'm assuming it isn't tied in). If the fill is not evenly compacted so it settles perfectly even, some parts will be loaded more than others and it will introduce tension loads. Also, how do you know the concrete is 2 1/2" thick? Mr Pe-Pe told you that?

The guy makes some great points. I'm nodding my head in agreement. Just set that wall in a bit from the pipe. Tolerate the lost footage. Then you won't have to worry. I'm putting in a brand new slab because I didn't trust my existing concrete... you're going to trust that, installed by those people, to hold up any amount of weight? :shock: My finished room will be 8' wide if I'm lucky. :roll:

Granted I'm not an engineer, but to my way of thinking - yes, the studs are offset toward the outer wall, and yes, the gyp layers aren't directly supported by the 2x8; BUT, I think the weight of the gyp will tend to pull the wall inward at the top, placing most of the bearing weight at the INNER edge of the studs, which IS centered on the 2x8. Also, I too wouldn't use this method if intending to rest a ceiling frame, etc, on it - I agree with sandersd about possible settling, unless the bottom of that trench is concrete. Even if you only consider the inner half of the 2x8, you're still at approx. 1 PSI, so I still think this could work - however, my first choice if this were my space, would be my old tried and true approach - LESS space that WORKS beats MORE space that's USELESS. This, whether you're talking about increased air gap for better isolation, or whatever... Steve

Andy, you may want to talk with your building department to see if they have an objection to it... :roll: ...If they do, then your decision is made for you! ;-)

Andy, why not just remove their portland mix - it shouldn't be all that hard. The chip back the inner slab and dowel some rebar into the wall and slab. At about 5" thick - all it would take would be some #3 deformed rebar to create a bridge that would simply span this and take it all out of the equation. The rebar should sit about 2" above the bottom of the new bridge slab and at 16" o.c. would be fine. 3,000# concrete would be good for the bridge. Then your wall could sit one inch away from the existing foundation without ever having to worry.. Rod

The chip back the inner slab and dowel some rebar into the wall and slab

Sounds simple enough. You could probably drill into the slab under the wall, but how will you drill into the inner slab? :? A right angle drill attachment? :roll: Too bad you can't just attach furring strips to the wall and attach the drywall to that... :idea:

Sandersd wrote:

Sounds simple enough. You could probably drill into the slab under the wall, but how will you drill into the inner slab? :? A right angle drill attachment? :roll:

Sandersd, you don't have to drill into the slab - all you have to do is sawcut it 5" deep (it looks 12" deep in the drawing) and then chip out the edge.... some 2" rebar stands will then do the rest. If it isn't 12" deep - and the scale is just screwed up in the drawing - then just cut it back 2' from the wall - and throw in a haunch that underpins the slab and pins to the wall........... That will do the same ting. I'll post a pic tomorrow. Rod

If it's a structural slab - then do this:

Outstanding idea! :D But a lot of work... :cry: If it were me I'd just move the wall in, insulate it, and be done with it. :wink:

Sandersd wrote:

Outstanding idea! :D But a lot of work... :cry: If it were me I'd just move the wall in, insulate it, and be done with it. :wink:

Sandersd, Not me buddy - no way I would throw away that kind of square footage. Not only that - but you have no gaurantee that the slab edge is structural - it might well crack and settle - because it was not poured intending to carry a wall. :wink: Rod

If the slab is non-structural then this:

Well if isolation is not a priority (earth on the other side of the wall), just screw furring to the wall and mount the drywall to that - maximum space and the wall carries the load to the fdn. If iso is desired, the additional spacing from the wall will help, so the space isn't really lost, just used for a different purpose. While your solution is certainly ideal, it seem a little overkill for its intended purpose - the cost/benefit ratio is a bit out of balance. A four inch reinforced slab is adequate to support a wall with a couple layers of drywall and no roof loads.

Sandersd wrote:

Well if isolation is not a priority (earth on the other side of the wall), just screw furring to the wall and mount the drywall to that - maximum space and the wall carries the load to the fdn. If iso is desired, the additional spacing from the wall will help, so the space isn't really lost, just used for a different purpose. While your solution is certainly ideal, it seem a little overkill for its intended purpose - the cost/benefit ratio is a bit out of balance. A four inch reinforced slab is adequate to support a wall with a couple layers of drywall and no roof loads.

1st off - he doesn't have a 4" reinforced slab - he has a couple of inches of grout over some crushed stone and a thin wall pvc drainage pipe. 2nd - with stone and pipe - and a wall load that will weight (roughly for an 8' height) over 40plf - you have no guarantee that there won't be settlement issues over time........ 3rd.......... building the wall assembly attached directly to the existing wall will increase flanking transmissions and decrease overall TL value of the wall assembly. Sincerely, Rod

1st off - he doesn't have a 4" reinforced slab - he has a couple of inches of grout over some crushed stone and a thin wall pvc drainage pipe.

The original slab, not the new section :roll:

you have no guarantee that there won't be settlement issues over time........

guarantee...

3rd.......... building the wall assembly attached directly to the existing wall will increase flanking transmissions and decrease overall TL value of the wall assembly.

Irrelavent to outside if earth on the other side. Regarding transmission to framing above, life is all about choices: how bad do you want it and how much are you willing to invest to get it - cost/benefit ratio. Since this discussion seems to have degraded from an offering of ideas into a defense of ideas, I'll leave it at that. Ultimately Andy will do all the work, or pay to have it done, and will live with the results of his decisions. If it's worth it to him your solution is certainly the most comprehensive in addressing all issues. :)

Sandersd wrote:

1st off - he doesn't have a 4" reinforced slab - he has a couple of inches of grout over some crushed stone and a thin wall pvc drainage pipe.

The original slab, not the new section :roll:

It was my understanding that he did not (as yet) have a new section - which was why Steve posted his sketch....... perhaps I am in left field and this work is completed.

you have no guarantee that there won't be settlement issues over time........ guarantee...

Sandersd, I cannot understand your position on this, earlier you posted:

wouldn't do it that way if it were me. I don't think the river rock keyed arch analogy will "hold up" to serious scrutiny- unless there is a foundation below the river rock, it will just be compressed into the soil below, especially if the layer of concrete topping is not tied into the existing slab. The pipe, if it is DWV with holes, will certainly deform under load.

You begin here by speaking in the manner I would expect an engineer to speak - especially a "blind one" (seeing as we cannot directly access the construction) - and now you're going to guarantee someone somewhere in the world that his (perhaps) 4" (perhaps) unreinforced concrete slab won't have any voids beneath it and won't ever have problems with settlement if a wall places a 40#plf load on it? How can this be?

3rd.......... building the wall assembly attached directly to the existing wall will increase flanking transmissions and decrease overall TL value of the wall assembly.

Irrelavent to outside if earth on the other side. Regarding transmission to framing above, life is all about choices: how bad do you want it and how much are you willing to invest to get it - cost/benefit ratio.

Agreed, however - seeing as this is not irrevelant to the inside of the house - and generally that is another area where the builder is attempting to create isolation from, and thus if something we suggest is going to compromise that - we (as the experts) have a responsibility to explain that to the poster.

Since this discussion seems to have degraded from an offering of ideas into a defense of ideas, I'll leave it at that. Ultimately Andy will do all the work, or pay to have it done, and will live with the results of his decisions. If it's worth it to him your solution is certainly the most comprehensive in addressing all issues. :)

No - you misunderstand me - I am not defending my ideas, nor am I attacking yours - however it is (to me anyway) important that the person asking the questions at least understands ALL of the posible outcomes that his descisions might bring upon him. It's useless for anyone to construct rooms within rooms unless they are willing to go the extra mile it takes for them to succeed.... it is truly a case of the value of the whole being determined by the weakest link. Thus, should the poster determine that isolation to/from within is not paramount - then he can proceed as you suggest, but in doing do he will also save a ton of money because he doesn't need to invest in any other special forms of isolation either. By the same token - should he require this isolation - then your method creates issues........ we just have to be certain to give him all the information he requires to make informed judgments - we cannot assume he knows enough about this to draw conclusions without that - other wise he would not be here asking questions. Sincerely, Rod

Let me first start by saying thank you. I feel honored to have all the heavy hitters in my thread helping me with this issue. Rest assured Rod and Sandersd, and everyone that has been participating; that through your discussion over the last 24 hours I have been given lots of information to make an informed decision on this awkward situation I find myself in. First, to be clear, the original Portland mix was poured at the time of the drainage system installation last month, but no further work has been completed yet. Also to be clear, I am no longer entertaining the idea of framing a new ceiling to sit on the new walls due to the additional weight and hope to use the RC clips. Also these perimeter walls need only be one of two layers of rock since there is already a cinder block and brick layer, and existing isolation to the outside appears to be superb! I am even consider using steel framing for these perimeter walls as well as internal walls if that will help reduce the weight. Additional background info: The existing slab is about 6 inches deep (I think) but I don’t believe it has any reinforcing in it. Is this what differentiates between a structural and non-structural slab? Having already spent 8000 unexpected dollars before putting hammer to nail (Asbestos removal, Termite treatment, and drainage system install), I am reluctant to spend too much more, additionally time is becoming a factor – I have the HVAC guys waiting on me to finish the ceiling beef up and wall framing so that he can get in to run the ductwork. Talking of which- an o.t. question while I think about it – If I used the RC Clips – how much extra space can I get below the joists? Reason I ask is that the fresh air intake duct (flex duct) that he ran seems to sit about 1 inch below the joist clearance. Anways, back to the question at hand. Even though I mention the time and money as factors, I still stand firm that I want to get the most I can from what I have don’t want to rush and jeopardize what could otherwise have been a great space. From reading your posts I see the following options: Building the wall assembly attached directly to the existing wall. – Not my preference for a couple of reasons. 1) Might increase the risk of mold growth behind the wall. I’m assuming that a larger air gap leaves more room for the space to “breathe”. 2) I am mostly concerned with a) TL between upstairs and downstairs, then b) between the Performance room and control room, and finally c) from inside the house to outside. It seems that this solution would decrease my isolation significantly for these and especially a, and b that are of paramount importance. Removing Portland Mix and adding “reinforcement” – This definitely seems like the sensible alternative. Of course this one is a bitter pill to try and swallow given that I just spent $4400 having someone cut into the slab and pour this stuff in there. I’m assuming it would probably cost at least another $3-4k to perform this solution. When I talked with the “Pee Pee Brigade” last week, then said that many of their clients frame new walls on top of their work in basement refinishing projects and they don’t believe it should be a problem. Of course in most other projects we would only be talking about 1 layer of drywall. So is the favorite? For me I really don’t want to have to go this route; but it’s definitely a contender. Framing new wall a couple of inches in from the Portland (i.e. 14 inches from the cinderblock) – Is this even still an option? Rod – were you suggesting that this might even be “iffy” if the slab is not “Structural” grade? If this method is okay, though I hate to lose the space this would definitely be a “safe” and quicker bet. I did also wonder whether I could recover some of my loss by using the space for storage. Somehow building some Mic and cable closets into the wall that would make me feel a bit better about losing so much real-estate. What do you guys think? So that is where my thought process is at right now. I’m not certain what exactly to do, but hopefully that gives you a better idea of my situation, needs, and thoughts. Next subject is my screwed-up beef-up. I’m hoping that you guys will forgive me for asking multiple questions in this one post, but this is a fresh one that requires my immediate attention. Though it is off topic, I have tried to bold print the key points / questions in my post to ensure it’s easy to follow. So, this weekend my friend and I completed our first “test run” beefing up a joist bay. It went great – mudded all gaps and cracks, first layer of drywall, mudded the seams, backer rod and caulked the perimeter, second layer of drywall with green glue, overlapping the seams, same backer rod and caulk to finish. Took us about 2 ½ hours for the one joist bay lol!!! Next day we came back and decided that we would take a more “assembly line” approach to the beef installation since I need my budding mostly for the drywall installation part more than caulking. So, we installed about 14 joist bays-worth of the first layer of drywall. Here’s the problem though. I had purchased 1 ¼ inch drywall screws to be used on the first layer and 1 5/8ths for the second layer. Unfortunately at some point I think we picked up the second batch (or they may have been altogether different as my buddy was fishing them out of his tool belt); and the end result is that now when I walk through my living room, the pergo floor feels like it is very springy in places. Kind like a spring loaded dance-floor if you’ve ever experienced one of those. I suspect that we have used the longer nails in places by mistake in places, and it’s pushing up the pergo (not sure why it didn’t drill into it???? Is there something else I could be missing? Another layer that is in-penetrable between the subfloor and the pergo?) Of course there are a couple of concerns here: 1) Damaging the Pergo 2) I’ve just created a 3rd leaf! 3) Potential hazard for people walking in the living room! So my question is. Do I have to go take out every one of the screws one by one, check it’s length and replace the offending ones? Or is there a quicker way you guys can think of? Is it possible that something else is going on? Help please! :? Finally I thought I was making some progress before finding yet another set back here. Doh!!!!

andy_eade wrote:

Next subject is my screwed-up beef-up.

Hi Andy, I just completed reading your thread all the way thru so now I'm caught up and can "maintain" daily updates as they happen and know what the heck is going on! You've had quite a run of bad luck and obstacle after obstacle. You've really handled it all so well. I'm sorry to hear about the latest snag with the ceiling beef up. That's actually why I came to your thread to do all the reading. I knew you were doing some beef up and I am at that stage in one of my walls and considering it in my ceiling so I was hoping to get the play by play instructions on how to do it properly from your thread. Then the word "cleat" appeared again and I almost ran the other way! :lol: I hope you get an answer to your current problem. In the meantime, I won't hijack your thread with my beef up questions, I'll post them on my own. But do you think you could take a picture of the one joist bay that you completed? I would like to see visually how you applied those damn cleats (!) and how it all looks. And would you mind posting exactly, step by step, how you did the process? Did you end up using GG? Exactly how did you apply the acoustical caulk - at what stage and was it around the perimeter of the drywall strip on 3 sides? Any suggestions based on your experience so far concerning the beef up would be helpful.

Hey Andy, Oh my, your laminate floor upstairs is in serious jeopardy. Unless the problem is solved, it's only a matter of time before you get some serous problems up there. I honestly see no shortcut around doing as you said -- removing all screws and rescrewing with the proper lengths. :-( I would keep walking on the laminate floor upstairs to an absolute minimum (prerably none) until the problem is solved. When I did my beef-up, I mostly did one layer at a time, rather than one bay at a time. And it is very time consuming... Deceptively so! :evil: I'm not quite sure how to further advise you on the wall thing... Rod's a really tough act to follow! 8) --Keith :mrgreen:

Andy, sorry to hear about the Too Long Screw mistake ... that is an easy mistake to make, I did it myself when beefing up my garage wall ... went outside and found a bunch of screws sticking out of my siding. OOPS :oops: It was difficult to figure out which screws I had done it on, but I had a decent idea because i hadn't done too much before discovering my screw up (hehe) ... but if you are really stumped then the only thing to do is get out the measuring tape, draw a map of the weird area upstairs and then remove screws from that area downstairs. as you remove the long screws just replace them as you go with the shorter screws, they should hold ok. on my siding, which is pretty soft wood, i didn't have any problem with that. of course if you feel that the holes are stripping out then caulk up the old hole and pick a new spot. at least you don't have to take down the drywall you've put up. how much would that have sucked if you put up the second layer before realizing the mistake ...

Andy, actually - you don't need any screws. If you screw a furring strip into the sides of the joist - tight to the underside of the drywall to support it - you could remove all of the screws. I do not reccomend the attachment of these sheets through the use of screws because you really want at least 1 1/2 times the fastened materials depth for pentration of the material holding the screw in place. ANything less and you are taking a chance of the screws working loose over time - especially in a floor which is constantly moving when in use above. As far as the concrete slab question goes........ If it's a reinforced slab - I would probably be comfortable moving the wall in - however - if it is not reinforced - a load on the slab edge could result in cracking and settlement after the work is all done. Remember - regardless of the stud type - 2 layers of 5/8" drywall run about 5.2 psf- so you are more than 40plf of load before framing just for drywall load with 8' high walls...... The choice is yours........ SIncerely, Rod

Rod- I had been adding 1x3 ledgers around the perimeter after the second layer of drywall was added. The screws were just to temporarily hold it in place while waiting for the second layer, backer rod, caulk and green glue etc. I did not plan to only use screws- rest assured! :) Should I be doing something different. I had originaly thought to put nails into the joist per the diagram in your book, but I couldn't understand how then to get the 1x3's in place if the nails are in the way - hence the screws. Reference the slab - how do I know if it is reinforced? Is there any clues I can look for? Thanks for you time Rod. Andy.

andy_eade wrote:

Rod- I had been adding 1x3 ledgers around the perimeter after the second layer of drywall was added. The screws were just to temporarily hold it in place while waiting for the second layer, backer rod, caulk and green glue etc. I did not plan to only use screws- rest assured! :) Should I be doing something different. I had originaly thought to put nails into the joist per the diagram in your book, but I couldn't understand how then to get the 1x3's in place if the nails are in the way - hence the screws. Reference the slab - how do I know if it is reinforced? Is there any clues I can look for? Thanks for you time Rod. Andy.

Andy... any way you could just add a couple inches of concrete over your existing floor? Maybe that would help? (by the way, i haven't planned on doing this).