ideas for these pics

hi. about 8 months ago i moved into a house in san francisco. as is typical to the area there are many old homes and old garages. my garage is around 100 years old. i'm converting it to a project studio of types. i've read several books including Rod's (one of the best imho). phase one was sealing the building so that rain didn't come in and getting an opossum out. no joke. phase 2 is underway. i am adding mass to all the walls between framing. 5/8ths drywall, backer rod, acoustic caulk. its a pain because the framing is old and irregular. but i am learning how to cut drywall precisely. some of this info is in my sig but from the outside of the building it goes: t-11, tar paper, 100 year old redwood siding, the 5/8th i'm adding. phase 3, will be a room within room with hopefully 2 5/8th drywall sheets on the inner leaf. i have a few questions. 1) there are areas that aren't practical for drywall. small areas, no place for fasteners.. please see gap pic. any ideas on how to treat that to match the 5/8ths? the gap is about 20'x2' just above the top plate of wall. it's due to the slated roof. 2) i found this sheetrock brand acoustical sealant at a gravel supply place. its super cheap, about $4 a large tube. its so cheap i wonder if its any good. i see that some people here have used it. 3) there are places where the wood from the old siding has rotted away. seems i should fill that before the drywall just to match mass. any ideas. there's spackle i guess. bondo too, but that stuff is hard on my liver. see damage pic. 4) anyone know what type of mass the roofing would add? i think its just the one layer of singles on top of tared 3/4 plywood, then old 1"x12" planks. unfortunately the roof is old 2x4 framing and can't take the drywall load. or so my contractor says. i believe him. you can kind of see in the photos whats going on. a large beam supporting the ceiling framing. my thinking is the walls used to be the least massive, least sealed areas, now the roof will be. thanks

You could seal the gaps by using mortar or any dry mix additive (concrete, gypsum) anyting that is MASSIVE Its easy to mix and to apply

Use Fixall. It's similar to bondo, but for construction. comes in a powder, dries very hard like cement. it will swell if filling large gap, come back just before setup and "shave" it down flush when using in finished areas. If you don't shave it down while semi hard forget trying to get it flat again. Mix just enough to use before it sets, about 20 min. Like the name says, you can fix a lot with the stuff.

good ideas. thanks. and these products could be spread on a wall to 5/8ths thickness and dry? is there such a thing as a gun for these? like a caulk gun i could apply the stuff like thick frosting? with fixall, i'm not sure. i don't want this to expand and warp the wood...like great stuff can around window frames. would any hardware store have fixall? it's late so i can't check the stores, but i can't fund much about it online.

Fixall is a "setting compound." It takes a long time to completely cure. But gets rock hard in 20 to 30 min. It won't swell that much. Just enough to make a high spot if your patching finished walls. Should be able to find at Ace or Home Depot. You could use a grout bag to Squirt it in like caulk but you would have to clean up thoroughly every 1/2 hr. A pan and knife for drywall are the tools to use. Hope this helps. :)

a 40kg mortar or cement mix costs about $5 us. You must add water and then apply it using a trowel.

cporro wrote:

3) there are places where the wood from the old siding has rotted away. seems i should fill that before the drywall just to match mass. any ideas. there's spackle i guess. bondo too, but that stuff is hard on my liver. see damage pic.

Water putty may be a better alternative. If you are thinking of using a mortar or concrete based product on a wooden product, then you would be doing yourself a favor to install 15# felt (tar paper) over the entire area to be prepared first. Which kind of defeats wanting to fill the voids ;) Reason being is that these two items do not play well together. Concrete has a history of sweat problems and water issues that rots wood. The most cost efficient is bondo for such a big area, but that is your call.

Fixall or fixitall says right on the bag it's for wood,plaster, concrete. Cheaper than bondo. But there are alot of carpenters that use bondo as a filler. If you got it use it. If not buy a bag and have it for other uses like when you do your drywall. $10 for almost 5 gal when mixed.

I was wondering how you attached your 5/8 drywall in between the frames. I've done a LOT of reading, trying to find this detailed. I'm not that handy, and I see you've done exactly what I want to do with my space (in terms of adding mass to the outer leaf). Can you give me some tips? Did you simply use drywall screws to hold it up and then use acoustical sealant around the edges? did you use the same 1/4" gaps at top and bottom reccommended in wall construction? Thanks! -Don

I was wondering how you attached your 5/8 drywall in between the frames. I've done a LOT of reading, trying to find this detailed. I'm not that handy, and I see you've done exactly what I want to do with my space (in terms of adding mass to the outer leaf). Can you give me some tips?

i got this idea from rod gervais' book home recording build it like the pros. he is talking about adding mass to a ceiling but its the same principle. i think i followed his concept but not his exact instructions. get the book if you don't have it already. money well spent.

Did you simply use drywall screws to hold it up and then use acoustical sealant around the edges?

no. if you start from the bottom and build up there is no need to actually screw through the drywall imo. there might be for a 30 ft wall but not for my walls with a max height of 11ft. i used ledger board (i think this is a generic term for a board that holds something in place) nailed to the framing. there are places where i added 2 layers of drywall and others where i added only one. the process was a bit different for each. how many layers are you adding? on the single layer i cut the drywall as tight as i could. the old framing is irregular so nothing ever fit perfect. then i cut 2" chunks of ledger board, pressed them tight to the drywall, and used a finishing nail gun to attach them. i can tell you the specs on the nails if you like. so the drywall was held firm against the wall. i figured it would be better to couple them then to have them semi loose. after that i used backer rod where the gaps where bigger then say 1/4". then i sealed up with acoustic caulk. i smeared it in with my finger to make sure there was a good seal. with 2 layers. i ran ledger board all around the drywall. caulked..usually no backer rod needed here. cut the second layer inserted this inside the ledger board, used 4d finsh nails to hold it in place, then backer rod and caulk.

did you use the same 1/4" gaps at top and bottom reccommended in wall construction?

not sure what you mean by this? can you explain? if you want i can post some close ups of what i've done. and i have a few tips. i'm about as new to this as you are except i've done lots of it over the last few weeks. i think its worth it to get one of those drywall squares for cutting. it makes a difference if your scores are straight and the knife scores perpendicular... the edges are less irregular. the nailgun is a big help. you can rent those i think and pre-cut the drywall. also the best value i've found for acoustic caulk is sheetrock brand. there is a sticky here somewhere with all kinds of caulk info.

I do have Rod's book. It's a GREAT resource (as is this forum). I've been sifting through it for the last 6 weeks! On page 66 he describes fitting the gypsum board 1/4" from existing joists and caulking all edges. I imagine this is for sealing it air tight To try and answer your question further, I've read in many posts that you should leave 1/4" space at the floor/ceiling/corners when putting up drywall. And then using the backer rod/caulk to seal the 1/4" gap. Anyway, I'm adding just one layer of drywall to the existing outer wall. Your idea makes sense to me, but if you wouldn't mind posting a close up, that would be great! I'm up here in Seattle and luckily have found a place that sells the Sheetrock sealant as well as resilient channel. And I do have a nailgun (from when I tackled DIY basboard trim), so I'll use your idea with the ledger boards. Hopefully within a week or so I'll post my own thread on the space I'm remodeling into a project studio. Thanks for your input!

sure, give me a few days for the pics. the 1/4" thing concerns me. i may have averaged 1/4" but it certainly isn't 1/4" uniformily. do you know what the thinking is on this? does it have to do with expansion/contraction? i did see page 66 but it's not explained. one thing that kind of surprised me about backer rod is it's use goes beyond saving caulk. apparently caulk works better if it adheres to only 2 sides instead of 3. something like that. so the backer rod makes the seal last longer.

Yeah the 1/4" thing. I do believe that part of the concept has to do with a building's movement. The use of non-hardening acoustical sealant provides a flexible seal that isn't necessarily broken if a wall moves gradually, right? Anyway, I'm planning on attaching my ceiling drywall to resilient channel. In this case I can see how a 1/4 perimeter with acoustical sealant might prevent flanking paths from the ceiling drywall to the connecting walls. But on the walls, I'm not using RC-1. I'm going to connect the layer to the studs. I'm still not entirely sure if the main point is sealing the wall air tight, or to mechanically separate the wall from the ceiling, floor, etc. If it's to mechanically separate the leaf, what about the fact that the wall is screwed into the frame, which is connected to the floor AND ceiling! I dunno, still till learning... -Don

But on the walls, I'm not using RC-1. I'm going to connect the layer to the studs.

Do you mean that you are going to attach the drywall to the existing (outer-leaf) studs? Or that you are going to build another (separate) stud frame to attach your inner leaf drywall to? If you don't do a separate frame and just put the drywall on the existing studs without RC, then you will not get good isolation.

I'm still not entirely sure if the main point is sealing the wall air tight, or to mechanically separate the wall from the ceiling, floor, etc.

Both! :) "Airtight" is a big part of it. If you have a really great 2-leaf MSM wall, with excellent isolation, and you drill a small hole aal the way through it, then you now have a lousy wall. The hole acts as a miniature loudspeaker. So hermetic sealing is important. And decoupling is important. If you have the same wonderful 2-leaf MSM wall as above (without the hole in it!), but you then drive a long nail through from one side so that it makes contact with a stud on the other side, then you now have a lousy wall. The nail "short-circuits" the two leaves, allowing vibration in either leaf to transmit to the other. in other words, it acts as a flanking path between leaves.

If it's to mechanically separate the leaf, what about the fact that the wall is screwed into the frame, which is connected to the floor AND ceiling! I dunno, still till learning.

Yeah, this stuff sure ain't intuitive! It take a while to get your head around it. As you point out, the floor is the common point, and does mechanically connect the inner-leaf and outer-leaf. That's why you want something really massive and well damped for your floor, such as thick concrete poured directly on grade. Thick concrete is very rigid, which governs for isolation at the lowest frequencies,it is massive, which governs isolation at higher frequencies, and it is damped across 100% of its surface by Planet Earth, which is very good! And since it is also coupled to Planet Earth, that kind of adds just a little bit extra mass.... :) So yeah, your floor is common to both leaves (unless you float an inner-leaf floor, and have a really large enough bank account and enough knowledge to do that correctly), but if it is thick concrete on grade then that isn't normally a problem. - Stuart -

close up pics... 2 layers w/ finish nails 1 layer w/ blocks. i'm kinda scared someone here will point out how i've just wasted $400 and 3 weekends. :D

Yeah, you just wasted $400 and 3 weekends. :) Not! :) Seriously, it looks fine to me. Neat caulking! Maybe you could have used larger blocks to hold the drywall in place, more along the line of cleats, but I reckon what you did is probably OK. Maybe Brien or someone else can comment on those blocks, but personally I reckon they should do the job. Worst case, you can just add a couple more, but probably not necessary. - Stuart -

yeah, i think i will make them a bit bigger from here on out. they feel pretty secure right now, but i'd hate if they popped out later on. in rod's book they have ledger board run full on each side. but those were on the ceiling. for me it's easier to use small chucks because both the framing and the cheap wood used for the blocks is somewhat irregular. that's the nicest thing anyone has ever said about my caulking.

that's the nicest thing anyone has ever said about my caulking.

That's probably because they haven't seen mine! :shock: Compared to mine, almost anything looks good.... seriously, it looks like you were not skimping, spreading it eavenly and generously, and getting it well sealed, which is all that matters. And straight lines, too! Damn! Wish I could do that...

Caulking takes patience and experience. The good thing about building a studio is, you get a LOT of experience :) You can finish sealant with the 'wet finger' technique. Take a cup o' water, add a little detergent (try to use detergent WITHOUT lemon). caulk the joint, dip your finger in the cup and whipe along the sealant to finish it of. Remember, a finished sealant like this can't be painted over (it can, but won't hold that good). And only works with acrylic seals. another trick is to cut of a piece of plastic tube (beveled) and "scoop" the sealant (I'll look up a video on that) Clean the joints before caulking, keep dust away. Kit flows better when it's not too cold (room temp.). Don't use too much sealant, make it in one go.

i was just using my finger. no water. and i try and get it in on go. but you have to wipe your finger off a lot. so i usually caulk as much as i can without it drying and then use my finger. in shifts. i remove as much dust as i can too. as much as the shop vac will clear anyway. those are some cool ideas, thanks.

yeah, it's sticky stuff :) (that's why you should use water with detergent)

Or wear gloves ;)

Or let somebody else do the job for you :mrgreen:

so back to the fixitall? patch-it-all idea. i got some. today as a test i used some. had a hard time getting it where it needed to be. so i wonder again, is there a way to pipe it in there? using a putty knife it messy and inefficient. maybe a tube i could fill and use in my large caulk gun.

cporro wrote:

so back to the fixitall? patch-it-all idea. i got some. today as a test i used some. had a hard time getting it where it needed to be. so i wonder again, is there a way to pipe it in there? using a putty knife it messy and inefficient. maybe a tube i could fill and use in my large caulk gun.

I bet you could use one of these: http://tinyurl.com/ms4tbs Keep us informed as to how this is working (if you use it). The whole "sweating" issue kinda scares me but who knows........ Nice work so far too!