Studio build in unfinished "bonus room" above garage

[robn]

CMunch,

I may not be understanding this fully.....I don't see the purpose of putting any air space behind the insulation if I have the soffit blocked off anyway.....sorry if I'm misunderstanding what you're trying to say. And IF the soffit was NOT blocked, wouldn't air find a way to get thru the insulation anyway? I was under the impression that it's not really "hermetically sealed" by the insulation.

Are you suggesting that I remove a little of the flooring at the extreme edges to allow for some airflow?

Let me know, appreciate it

 

[RICK FITZPATRICK]

Easiest way around is to make sledges with 45 x 38 or similair battons and 4mm ply,

Like I said. Studios in an attic space are a compromise if you need isolation.

ie.........the SLED creates a 3 leaf system.

Besides, if the soffets are blocked at the floorline, whats the point.

 

[MikeA]

Inulation along the roofline

What CMunch is talking about is what I was alluding to a couple of weeks ago. Sorry not to get back sooner, had a new granddaughter and my two boys both started football, so it's been nonstop around here.

Common construction practices dictate that inside the roof line needs an airspace to prevent moisture buildup between the warm air inside a house and the cool air outside (in the winter), and excessive heat to the shingles in the summer which can reduce their life. The trapped moisture can lead to dangerous mold growth which can cause breathing problems like asthma.

Check out this page for an explanation of what I'm so poorly trying to describe. If you've got the soffits blocked off you may be setting your house up for some other problems down the road.

http://images.google.com/imgres?img...ox-a&rls=org.mozilla:en-US:official&sa=N&um=1

This page explains it a little differently and provides some other images to help clarify:
http://www.southface.org/web/resources&services/publications/factsheets/25_insulateceilings_4pdf.pdf

Mike

 

[robn]

Mike,

Hey, congrats on the new addition!!! Sounds like you've been pretty busy lately.....I know how kids can take up your time, I have 2 daughters myself (they are 22 and 25 now though)....

Does this baffle go at the bottom or does it need to run the entire length of the rafter behind the insulation?

 

[CMunch]

Sorry I didn't get back to ya dude, looks like MikeA has it covered,

The baffle shown on that diagram is typical of one used when the loft space is not used as living area in a property, glasswool expands in varying temperatures and the purpose of that baffle is to stop the loft wool placed along ceiling ties expanding and closing off soffit vents.

It is basically a sledge like the one I sketched but it is typically only about 600mm long, as that is enough to sit above the wool level in a loft which is not used as living space.

In your setup the sledges would have to start where shown in the diagram and go just above the insulation on the new ceiling you create.

 

[robn]

So, you're saying that 1) I need to take the flooring off of the area above the soffit board, then 2) put a sledge starting at the floor level that runs the 10' or so on my west wall, and 3) do this for every one of the vertical rafter gaps (about 7-8)?

Alot of work if true, and I'm just trying to make sure I understand.....thanks

 

[CMunch]

So, you're saying that 1) I need to take the flooring off of the area above the soffit board, then 2) put a sledge starting at the floor level that runs the 10' or so on my west wall, and 3) do this for every one of the vertical rafter gaps (about 7-8)?

Alot of work if true, and I'm just trying to make sure I understand.....thanks

Pretty much dude, honestly not much work when you get started, if you have a hole saw just bore about 5 or 6 40mm or so holes through the flooring in each rafter bay, too much hassle to try and remove it now, did you notch the flooring around the rafters?

If you post a pic of where your flooring meets the rafters I can see what you have and I will post a more detailed sketch of what you need to acheive.


Very nice looking house by the way.

 

[robn]

Well, this is about the best pic I've got......I caulked around the rafters so there's no hole there....

This may be a crazy idea, but what if I drilled a 2"-3" thru the flooring at each rafter bay, put a 2" or 3" PVC pipe in the hole, drill holes in the PVC, then run the pipe all the way up the rafter bay attaching to the sarking with a regular pipe attachment (with short screws ). That way it would take air from the outside but the sound leakage would be somewhat minimized, since the sound would have to go thru 2 5/8" layers of sheetrock, thru the insulation, down the pipe, and out the soffit board holes?

I know it sounds crazy, but would it work? BTW, I'll have to do this on both the west and east sides......

Thanks for the comment on the house......

 

[CMunch]

"Short screws"

I cant see any reason why that wont work bud, the pipe would hold the insulation away enough for air to move, dont bother with the bays at each end where your gable ladders are, the timbers run across the way on them, nobody vents those bays.

If you do go with the pipe idea, bore the hole through the floor 10 mm bigger than diameter of the the pipe, flooring also expands and contracts, if you make it tight it will eventually squeek on the plastic pipe and you wont be able to get to it , drive ya nuts, DONT CAULK IT.

 

[robn]

Yeah, if I use long screws I'll definitely have a "moisture problem"

 

[CMunch]

Yeah, if I use long screws I'll definitely have a "moisture problem"

Dude, couple years back I was building a real fancy golf pro's shop and driving range, main part of the building was octagon shaped with high exposed rafters, cos everything was exposed we got some real nice hardwood sarking, clearly marked on everyones drawings and highly visible, roofer still managed to get about three hundred 90mm paslode gun nails protruding through it when fixing tile batons while I was off site.

I didn't kill him though, paramedics revived him easily after about two or three minutes.

 

[robn]

I didn't kill him though, paramedics revived him easily after about two or three minutes.

I would say that 2-3 minutes without air would start to kill off some of his brain cells, but, well, it doesn't sound like he had that many to start with


BTW, I did find a better pic of the floor....it's from 3 years ago when I started this:

 

[RICK FITZPATRICK]

This may be a crazy idea, but what if I drilled a 2"-3" thru the flooring at each rafter bay, put a 2" or 3" PVC pipe in the hole, drill holes in the PVC, then run the pipe all the way up the rafter bay attaching to the sarking with a regular pipe attachment (with short screws ). That way it would take air from the outside but the sound leakage would be somewhat minimized, since the sound would have to go thru 2 5/8" layers of sheetrock, thru the insulation, down the pipe, and out the soffit board holes?

Robn. I'd submit, you have a lot of input here. Your studio is an unusual set of construction circumstances. Now comes the time to decide which is more important. In reality you have many concerns. I would also submit that for every set of construction considerations, there is a equal consideration in
TL/time/money. At this point, I think I'm going to lay off suggesting any more directions untill such point I can actually be of help. You obviously have some important decisions to make. Should you need any ...give me a holla. I think I've highlighted many considerations, but now, you have some valid input into the value of your home vs compromises.
fitZ

 

[robn]

Rick,

Well, here's the deal......I had someone here locally tell me the same thing that MikeA and CMunch have mentioned...HOWEVER, he wasn't exactly the best authority on building......I disregarded his advice.....now though, I'm hearing the same thing from several people, so I have to at least consider this.......I'm not worried so much about the moisture issue as the heat issue.....it gets REALLY hot here......so I'm probably going to do the PVC idea......I think the TL would be minimal with the PVC design.....

Hey, don't step back now!!!!!!!!!!!!!! I'm just waiting on you to find out from those guys you were going to talk to......have gone over to StudioTips but didn't see anything from you yet.......

Like I've told you before, at this point I'd be willing to take the flooring up and put some type of isolator/spring/whatever if it will help.

But senor, don't back out on me now!

 

[MikeA]

Rick,
I didn't mean (and I feel certain that CMunch didn't either) to redirect his attentions or dilute anything you were saying here. We just noticed something that could cause some potential problems for Robn. We just didn't want Rob'n to get too far down the road to address this problem and then have to tear things out to fix it later. He's had at least 3 people mention the same thing to him and it's a lot easier to tear out some insulation and fix whatever the problem is than to get the drywall up and THEN have to do it.

Robn,
Actually, I think CMunch has a better handle on it than I do; his ideas come from practical real world experience, mine are just things I've read about over the years of studying this stuff. That and I was up in a friend's attic a few months ago and they were preparing to finish out a bonus room when I noticed the roof vent baffles. It was then that I really understood what I had been reading about.

CMunch,
I think I may be a bit slow on understanding because of terminology differences but I think we're talking about the same thing here. Where I come from a Sledge is something we use to beat something into submission. The best I can tell, you meant a sledge to be the formed roof vent baffles. And, well, I've never heard of Sarking, but it appears to be what we call decking on the roof. Please educate me if I got those terms and what they are screwed up.

Robn,
I would think that doing what you are talking about with PVC will work and, it might be easier than trying to get a jig saw down close to where the roof meets the subfloor of your attic to cut the slit for the roof vent. Drilling holes in the PVC along it's length And as long as you tighten up the knee walls that you build (caulk at the floor, etc) and are careful with the installation of the drywall on the ceiling to minimize sound leakage you should still have a quiet room. You can still put insulation up in the rafter bays after you've given the soffits and the rafter bays a way to breathe.

 

[RICK FITZPATRICK]

Well, here's the deal......I had someone here locally tell me the same thing that MikeA and CMunch have mentioned...HOWEVER, he wasn't exactly the best authority on building

Neither am I. That's why I thought it would be best for me to wait till you sorted this issue out.

I disregarded his advice.....now though, I'm hearing the same thing from several people, so I have to at least consider this.

Absolutely. I hope you didn't take me wrong. At no time would I advise doing something in regards to TL that would compromise the longevity and or comfort of your home in any way.

it gets REALLY hot here.....

I can imagine.

.so I'm probably going to do the PVC idea......I think the TL would be minimal with the PVC design.....

Lets examine this idea. Give me a day to draw it up so I can see just what you are dealing with. I really haven't had time to give it some thought. HOWEVER, something occured to me in the middle of the night.
At one time, John Sayers told about a studio he built that HAD to have a three leaf exterior envelope by virtue of the fact the building was shiethed with old board and battens. There were many "flanking paths, but he solved the problem by installing drywall in the stud cavitys between the studs. The concept was a "vented" third leaf. Now, that MAY be an answer here as well.
However, that remains to be seen. What I'm really wondering about is:
1. What the eave framing is like and or is there blocking that blocks off the eave in the first place.
2. How ANY type of venting between the soffets and your ceiling/attic/duct space could vent HEAT from that area as you don't have any vents at the ridge. Heat rises. Maybe I'm missing something here. And yes I understand about the moisture thing. However, HOW can it be prevented simply by having vents at the soffets up to the attic space if air in the attic doesn't move upward via a ridge vent.

Hey, don't step back now!!!!!!!!!!!!!! I'm just waiting on you to find out from those guys you were going to talk to......have gone over to StudioTips but didn't see anything from you yet.......

Ok, no prob. I was waiting to see how this issue is resolved prior to posting at Studio tips. I don't want to look like an idiot by having to go back and change things after posting. I think you know what I mean Robn.

Rick,
I didn't mean (and I feel certain that CMunch didn't either) to redirect his attentions or dilute anything you were saying here.

No problem. I'm glad you brought this up NOW, vs later.

Gotta go now, but I'll be back tonight. Tons of work to do today.
fitZ

 

[RICK FITZPATRICK]

PS, sorry to post pics that arn't compressed and resized. No time.

 

[RICK FITZPATRICK]

It just occured to me.

 

[RICK FITZPATRICK]

It would appear that you COULD drill some holes at the floor to vent the soffits into these areas, and run PVC from these areas up to the "attic" space? But you still don't have a vent at the ridge or gabled end.

 

[CMunch]

Totly agree with MikeA, RICK is a very cool and helpful dude and I was in no way trying to undermine him.

Just that I have came across this before and it is an expensive remedy further down the line. Wouldn't sit right with me if I had noticed and ignored.

MikeA, yea you have the terminology correct, sometimes it's hard to make a point on here what with you all speaking a foreign language.


Robyn dude, everything else looks a1 and I'm pretty sure RICK will get ya the rest of the way.