Basement studio-room project in Boston area

[sharward]

I'm pretty sure that wood hardens as it ages and dries. Your new lumber was probably pretty "green", thus easier to drill through.

[Luftweg]

For documentary purposes, here is a bridge that was washed-over.
It is about 1/2 mile from my house.

The street I live on also had about 2 feet of water across at the worst time of the event (at the lowest point of the street); it had actually become a small pond at that point, connecting yards on both sides of the street (where the water was even deeper in the backyards of those houses).

My house is one house up from that! (note: I don't mean from these pics; alas, I don't have the pics of my street).
But with the dual sump pumps we nary saw some pretty minor seepage around the perimeter of the basement...
This was a good test -- a '100 year flood', as they called it.
Certainly, however, part of my work will be devoted to installing perimeter 'gutters', like Drytrak or SquidGee, that lead to the pumps.
It was a wake up call for sure.
All the talk you hear or read about making sure your basement is dry, before you begin serious finishing work, should be heeded.

K

[sharward]

Wow... That's downright frightening.

I worry about this a lot here in Sacramento, particularly in our part of town.

From our local newspaper in a recent multi-part series:

• In cities across the nation, rivers, streams, lakes, creeks and seas have made their sinister mark, inflicting damage and heartache when they flood.
  
  There is, however, no major city in America more at risk of a catastrophic New Orleans-style flood than Sacramento . . . marked by a potentially deadly combination of geographic, hydrological and demographic factors unmatched anywhere in the United States.
  
  . . . places such as Natomas, downtown, east Sacramento, Rosemont, North Sacramento, Oak Park, Curtis Park, Land Park, River Park, Greenhaven, the Pocket, south Sacramento and assorted neighborhoods along the north and south sides of the American River would fill up like giant soup bowls during a disaster-level flood.
  
  Sacramento's levees offer less protection than those in many other cities. . . Engineers discovered after the floods of 1997 that seepage is occurring deep beneath Sacramento area levees that could cause internal erosion and unforeseen failures.
  
  Beyond the levees is another concern: Folsom Dam, which holds back the American River to the east of the downtown core, is ranked No. 1 on the federal Bureau of Reclamation's safety priority list. With nearly a million people living downstream, no other dam in America has greater need of additional protection against a monster storm . . . a major flood in Sacramento would spread for miles and run as deep as rooflines in some places. . . more than 300,000 people and 140,000 structures are in the direct path of a serious flood in Sacramento.
  
  In the eyes of the nation's top flood experts, only one other big city could rival Sacramento for the top catastrophe-prone title.
  
  And it has been largely destroyed.

My heart goes out to those in your community whose lives have been turned upside down due to the flooding. I had plumbing fiasco two years ago that expelled us from our home for several weeks during the repair work, and that's nothing compared to what some of your neighbors are going through now.

And it's nothing compared to what we might have to go through here in the future...

I'm glad you escaped disaster. That was a very close call indeed.

[knightfly]

Luftweg, check your post about steel studs for an important link... STeve

http://www.buildingscience.com/resource ... ldings.pdf

(just in case)

[Luftweg]

Okay, so I'm getting more near to the point where I will be blocking access to parts of the concrete floor and walls...

To reiterate, the house is 1959-60 construction.
12-14" thick poured concrete walls, with poured concrete floor.
I 'assume' there is no vapor barrier or damp-proofing on the outdoor faces of the concrete....

So, how should I treat the concrete?

There is currently a black colored sealant on the inside face of the concrete.
For much of it, it is intact, but in areas where the 'old' finishing work was(studs with kraft-faced fiberglass batts) there are a few spots where it has peeled off and some lime seems to have leeched through.

The basement has only within the last 3 years been keep 360 d/yr dehumidified, and I again 'assume' that there has been condensation behind the stud walls before this.

Should I treat the concrete with something, just paint it, or.....?

Of course, as the new stud walls go up there WILL be a 3 inch space between them and the concrete walls.
In this space will be a perimeter gutter leading to the sumps; I'm also intending on somehow venting this area (?)...

thanx for any thoughts,
K

[Luftweg]

I don't really know personally people who were hard hit, but there have been many casual reports of several feet in peoples' basments that I have heard...

I do have to be thankful that I really didn't get anything aside from the small amount of seepage around the perimeter;
the perimeter gutters should take care of that.

We are dealing with a 70-100 year storm, and if my sump pumps and drainage kept up this well, all I should really need is a bit of tweaking and back-up systeming to feel confidently safe (this includes battery backup for power outs, other redundancies and provisions, and making sure the water heater has a pan and drain to the sump (it's so far away from the studio, and so near one of the pumps that that would be just icing, but who knows?).

[Luftweg]

Update:

I'm at the point of cutting the REALLY hard oak flooring nails that poke through the bottom of the subfloor (of the above room), so I can place the sheetrock in the between-joist spaces....
Still looking for the ideal way to cut them flush, and there are quite alot of them, so the method has to be fairly efficient...
Any ideas?...

After the sheetrock gets up, the perimeter gutter on the basement floor needs to be installed...
As I stated before, I'm looking toward surface-mounted (or near surface-mounted) PVC type stuff...
The commercial stuff specifically made for this is kinda expensive, and I'm trying to get my brother (who works in plastics designs) to help me find a suitable material that will be as effective, but cheaper (angle PVC?).

I may probably try to cut or grind about a 1/4 to 1/2 inch depression or taper at the junctions of the wall and the floor (to allow any seepage to fall into; the middle of the floor doesn't seep, and there is very very limited seepage on occaision only at the junction of the floor and walls during special rainy or thawy events)...

The inner-leaf walls would be interior to these gutters, and I'm hoping to be able to vent this area to some degree (yet maintain a high degree of isolation of the between-leaf 'dead' air space); as an idea, I thinking of possibly using some low-volume/low-velocity blower through long, highly angled/curved tubing and then through truck mufflers (crazy-sounding huh?.... although I think the idea has some merit (if you know how loud trucks/cars can sound without mufflers -- and how quiet they can be with them on -- you will know why I'm considering this)...

The entire basement is dehumidified, but the area between the concrete wall (outer-leaf) and stud wall (inner-leaf) would be pretty sealed-up...
I don't want to seal-up any seepage or condensation behind the stud walls...
Venting that area would exchange its air with the dehumidified air of the basement interior and keep it dry....

NOW, how do I go about grinding the concrete???
I have some ideas, and I think they rent tools for this operation (and yes, I know it can be pretty dusty)...
Anyone do this sort of thing before?

thanx,
K

[Luftweg]

Hi:

I have been pondering what, if anything, I should use on the inside surfaces of the poured concrete of the basement walls and floor...

Alas, on the internet there are so many sites saying use this (usually their product) or that...

Anyone have ideas of what to use as an interior surface treatment, considering that the outside surface is most likely completely un-treated (no waterproofing, barriers, insulation, etc.... just concrete in contact with the earth)...

thanx,
K

[knightfly]

Kenni, can you post a few pix of the OUTSIDE of your place? Specifically, show any rain gutters, down spouts, slope of the earth within about 5 feet of your basement walls, any window wells, etc - I need to see what kind of drainage your place has and the condition of your OUTSIDE wall surface, etc... Steve

[Luftweg]

Kenni, can you post a few pix of the OUTSIDE of your place? Specifically, show any rain gutters, down spouts, slope of the earth within about 5 feet of your basement walls, any window wells, etc - I need to see what kind of drainage your place has and the condition of your OUTSIDE wall surface, etc... Steve

Will try to take some representative pics soon of surrounding ground of concrete walls, etc.; we've been getting loads of rain lately again...
(do I understand correctly that you want a pic of the concrete walls inside of the basement... or is that the outside of the house? both?)

I DO know that there are existing issues with grade, downspouts and such, from before I took over the house...
And I am (and will be) working on those as well...

I understand that a major amount of keeping a basement dry is related to keeping the water away from the OUTSIDE first... and then one addresses any water that might still make it's way in...

(until I get pics up...)
Specifically, all the downspouts terminated at the bottom; that is, there were no bends or extensions -- the water ran right down the side of the house!
I have fixed 2 of those by routing them into pvc pipes that I burried to run 10-15 feet away to dry wells that I dug also; the others have been (temporarily) fitted with 60 degree angle adapters and spout extensions that are 10 feet long...
(I thinking of amending the plans to have all the underground pvc pipes resurface to daylight, at a lower grade -- to avoid any potential blockages of the pipes or drywells, from roots, silt, etc.)
There are some spots around the house where the ground actually angles toward the house, instead of away -- so I know that that is something to fix as a project for this summer... temporarily I have dug small trenches to duct water away...

How does one create the best watershed alongside the house?
Should I fill will soil to create the slope, tamp it, then cover it over with some sort of plastic sheeting, and then bury the plastic with layer of gravel and then more soil?

thanx for any help...
K

[knightfly]

Sounds like you're on the problem; somewhere Rod recommended a particular fix for watershed, but I'll be damned if I could find it - don't remember what material he recommended

If you have the Building Sciences pdf's on "before you build, etc" (see the REFERENCE section for links) they cover this pretty well with illustrations, etc... Steve

[Luftweg]

I'm getting close to the time where the ducts above the studio will be replaced with the Johns Manville Superducting.
These ducts will supply the above room only and NOT the studio.

Placing the ducts between the leaves means that some cross-sections through the ceiling WILL involve other than 2-leaves -- this is unavoidable
(please don't simply comment on this fact... UNLESS you can design a way to have the duct between the leaves and not have anything else but a 2-leaf cross-section at any point).

SO, in other words, some cross-sections connecting 2 points will be either across 2-leaves or 3-leaves, or possibly only 1-leaf, or as great as 4 leaves).

I have created 4 different diagrams of possibilities, which will help visualize the compromise that HAS to be made...

I obviously want to make the best compromise.

SO, is it better that:

1.) The inside of the duct be 2-leaf with respect to the studio, and single-leaf with respect to the above room?

2.) The inside of the duct be single-leaf with respect to the studio, and single-leaf with respect to the above room?

3.) The inside of the duct be single-leaf with respect to the studio, and double-leaf with respect to the above room?

Remember (although I don't know how much it would apply), I'm trying to block sound coming OUT from the room and going into the above room(s) and not really the reverse.

It seems to me that sound that gets into the duct is NOT equivalent to sound that gets through the above floor because the sound that gets into the duct has to travel to the end of the duct and come out the register...
The superduct will likely attenuate some of that sound it would appear...
Alternatively, sound that does gets into the duct may not pass that well straight up through the duct and then through the floor, but may better pass through the length of it and out the register.

Diagrams:

1.) Simply 'ignoring' the duct's presence and placing the sheet-rock between the joists in the same position across the board (i.e., whether there will be a duct there or not).

2.) This is the same as the first option, but adds an 'extra' layer(s) of sheet-rock below the duct, creating a 2-leaf system between the duct and the studio.

3.) Here there is no sheet-rock along the subfloor, and the duct is moved up against the subfloor; sheet-rock is added below the duct.

4.) Same as the previous option except the layer(s) of sheet-rock below the duct are thicker.


[Note that in the diagrams any between-joist- and fire-blocking and insulation is omitted for the sake of clarity -- these of course would be used in the actual construction]

thanx for any help, as usual,
K

[Luftweg]

Steve, is this what you had meant?

Again, I just want to verify that this will prevent as much sound as possible (or at least making it a more controllable sound) entering the duct...
I'm afraid of the sound through the floor directly being well controlled, but that sound entering the duct will travel through the duct and out the register, bypassing the floor.
Am I mistaken?

thanx,
K

[sharward]

On second thought... Maybe all the beef should be below the duct, as you have in image number 4?

Sorry for the confusion and for contradicting myself and contradicting Steve. Please don't make a move on this until there's consensus.

--Keith

[Luftweg]

On second thought... Maybe all the beef should be below the duct, as you have in image number 4?

Sorry for the confusion and for contradicting myself and contradicting Steve. Please don't make a move on this until there's consensus.

--Keith

Keith, I promise I WON'T start anything with the ducts until I have this matter resolved

Steve was unaware that the duct would NOT be supplying the room, and in fact would be supplying a room that I don't want sound to get to....

Because now he knows that, he has changed his recommendation.... which I believe IS more like #4....
That seems to be running toward a consensus, because there are now 3 people who all point to #4...

.... Of course, there is still a bunch more 'refinement' of things, even if #4 is chosen....

thanx,
K