Building a functional timber-framed home with wrap-and-strap?

[Palmetto]

Greetings!

I'm trying to understand how to make all of the housing systems work together (i.e., frame/insulation/cladding, with plumbing/electrical).

So, to start: I'm interested in building a timber-framed house at some point in the next few years.  From my research, it appears there are only two recommended ways to insulate: SIPs or wrap-and-strap.  SIPs probably won't be an option due to the cost.  I'm envisioning a wrap-and-strap approach that goes frame -> interior wall cladding -> ZIP (or similar) -> a few layers of horizontally/vertically offset foam -> strapping -> siding.  That seems pretty standard, based on what I've read/watched.

Here's where my confusion/frustration comes in: this method leaves your house very airtight, which is great in a lot of ways, but also leads to a ton of questions, but I'm going to focus on just this one (for now).  

(I'm going to assume we're building over a basement with I-joists, and then a 2-story timber frame on top of that.)

• What, as a timber framer, do I need to do to help the electrician and plumber do their jobs?  I want to have all of my timbers fully exposed.  I'm sure they can use the I-joists in the basement to do whatever it is they do in the basement -- but how is that passed up to the first floor ceiling/second floor? 
  Again, I'm thinking about this in terms of, "How can I prepare this structure in a way that will help them" (e.g., adding I-joists above the first floor, or carving a channel in the reference face of a timber, or whatever), not necessarily about the tradesmen's specific actions.

Thanks in advance!

[Jim_Rogers]

Some details are here:

Electrical stuff - (forestryforum.com)

TF Enclosure systems - (forestryforum.com)

Jim Rogers

[Palmetto]

Some details are here:

Electrical stuff - (forestryforum.com)

TF Enclosure systems - (forestryforum.com)

Jim Rogers

Thanks for that!
Looking at the plumbing diagrams, I want to make sure I'm understanding correctly.
To plumb bathrooms according to that, you'd:

• align all bathrooms vertically (more or less)
• put the pipes on an interior (non-timber framed) wall
• raise tubs/showers up so that the pipes will fit under (and, thus, the timbers will still be visible from below)

If I'm understanding correctly, the timber frame itself wouldn't need to be adjusted, right?  You'd actually just use the interior walls.

I'm still looking at the electrical details, but these are really helpful.  Thank you!

[Jim_Rogers]

Raising the bathroom floor is one way to do it.

I saw another who ran the plumbing pipes below the floor and between the joists, and hid them by placing some boards between the joists. These were set in grooves in the bottom of the timbers, so that the boards could slide left or right an inch or so, and then drop out of the opposite timber's groove. That way they could access the plumbing from below if needed. And they were hidden from the first floor looking up.

Sort of like a lowered wooden ceiling made out of small wooden panels, that are removable.

Jim Rogers

[Don P]

We call that a "tray".

[DangleSnipe267]

Jim,

I'm curious what text those diagrams plumbing and electric chase diagrams are coming from. Are you willing to share? 

Thanks,
Tim

[Jim_Rogers]

Jim,

I'm curious what text those diagrams plumbing and electric chase diagrams are coming from. Are you willing to share?

Thanks,
Tim

I can't remember where I got them. Sorry.

[Don P]

This is another tray. There is a bathroom above and that is a "wet" wall behind the cabinets. aside from plumbing there is an HVAC lineset, electric and gas in the wall. That could have also been a boxed soffit or tall cabinets there.



 

That's another wet wall, it sits behind the structural timberframe. To the right of the bedroom door is a bath and the master bath below it. And another lineset to a minisplit upstairs.

[Don P]

As I look, two things. The wet wall extends to the underside of the roof SIPs here, the vent stacks run straight up and out from those walls.

The stair rails. Charlie was cool. He admired them and then slapped the top rail a couple of times on his way up. They are a fine guard rail but are not a code compliant handrail, he was just winking. At the time it was just the girls upstairs. Later the girls married and Mom came to live with them. Either out front of those or on the opposite wall do have a strong graspable rail alongside stairs. I saw after posting the pic and couldn't let that go without a "don't do that".

There we go, this is in the apartment above the garage there, a guardrail over the pit and a "graspable" handrail down the run.



 

Back on topic, co-ordinate with the trades early on their preferences but basically keep the plumber and tin knockers out of the exterior walls if possible.

If I need to track a wire down the top of a beam do no more damage than necessary. In some places you will need to put the wire in conduit. FYI, you can shoot a nail through conduit, it doesn't let you be any less dumb later if you bury a wire. I prefer to put a block flatways between framing members, cut a recess for a ceiling box, secure that and the block between joists or rafters or purlins and turn that wire chase running down the bem out onto the block and into the ceiling box. Less damage to the timber, I didn't drill a hole through it... and they always want the thing hanging out in midspan, where punching a hole through a perfectly good timber is... nuts  :D.

You ain't gonna win that one every time. That pretty arts and crafts entry light dangling in the pic above. Is dangling from a hole punched through the exact middle of the purlin in the roof there. I had lost the discussion and called the engineer. I could hear the slide rule smoking and he allowed me one centered nicely drilled 5/8 hole, the wire went through 1/2. Figure that stuff out ahead of time, deduct for loss of net section, don't chop box recesses into beams, we hung that fixture from a surface mount pancake box. Know your box fills, I've been busted on a log home job and had to remove every receptical box, chisel deeper and put in a deeper box, too many wires in too small a box, easy fix in sheetrock, tougher as you get more exotic, but its all an education, the tuition is higher on the jobsite

That was probably more than two things  :D

[Palmetto]

As I look, two things. The wet wall extends to the underside of the roof SIPs here, the vent stacks run straight up and out from those walls.

The stair rails. Charlie was cool. He admired them and then slapped the top rail a couple of times on his way up. They are a fine guard rail but are not a code compliant handrail, he was just winking. At the time it was just the girls upstairs. Later the girls married and Mom came to live with them. Either out front of those or on the opposite wall do have a strong graspable rail alongside stairs. I saw after posting the pic and couldn't let that go without a "don't do that".

There we go, this is in the apartment above the garage there, a guardrail over the pit and a "graspable" handrail down the run.



 

Back on topic, co-ordinate with the trades early on their preferences but basically keep the plumber and tin knockers out of the exterior walls if possible.

If I need to track a wire down the top of a beam do no more damage than necessary. In some places you will need to put the wire in conduit. FYI, you can shoot a nail through conduit, it doesn't let you be any less dumb later if you bury a wire. I prefer to put a block flatways between framing members, cut a recess for a ceiling box, secure that and the block between joists or rafters or purlins and turn that wire chase running down the bem out onto the block and into the ceiling box. Less damage to the timber, I didn't drill a hole through it... and they always want the thing hanging out in midspan, where punching a hole through a perfectly good timber is... nuts  :D.

You ain't gonna win that one every time. That pretty arts and crafts entry light dangling in the pic above. Is dangling from a hole punched through the exact middle of the purlin in the roof there. I had lost the discussion and called the engineer. I could hear the slide rule smoking and he allowed me one centered nicely drilled 5/8 hole, the wire went through 1/2. Figure that stuff out ahead of time, deduct for loss of net section, don't chop box recesses into beams, we hung that fixture from a surface mount pancake box. Know your box fills, I've been busted on a log home job and had to remove every receptical box, chisel deeper and put in a deeper box, too many wires in too small a box, easy fix in sheetrock, tougher as you get more exotic, but its all an education, the tuition is higher on the jobsite

That was probably more than two things  :D

I don't need to know now, because I'm a long way from even starting this process, but if you happen to know any good plumbing/electrical guys in the Boone area who understand timberframes ...  ;D
Going back to something mentioned earlier (raising the second floor), would it be crazy to put in a layer of floor joists between the first and second floor for the whole house?  I know that's overkill (there are already timber floor joists), but I also wondered about adding rockwool or something for soundproofing between floors.  I'm sure that'd probably be expensive, though, even if it is feasible and logical.

[Don P]

@logman probably has contacts y'all can PM. I don't wander over the border but I know some guys that do work over that way if you need more refs.

On the house above, the upper bedrooms are 2x6 T&G over the timber joists you saw in the kitchen. The plans called for sound deadening board over that. Not needing enough for a minimum order of something seen I'm sure on HGTV :D, with the client's blessing we installed 3/4" blueboard foam over the T&G, then 3/4" Advantech (very stiff/flat osb floor sheathing) I snapped an 8" grid and went to town with a screw through everything into the T&G, be mindful that is the ceiling below, check screw length carefully. Then pad and wall to wall carpet. I'm going to guess that because there are no solid framing members connecting face to face that is quieter than frame over frame. Frame, sleepers, etc can give you chases for electric or plumbing. It also eats headroom, raises stairs... it is one of those look at everything it affects things.

[logman]

Since you are building near Boone don't discount sips.  I get mine usually from Johnson City, Tn.  Very close to Boone to cut down on shipping plus they have the best prices of any other sip manufacturer that I have found.  Using sips if you pad out the back side of the frame to slide t&g or sheetrock it gives you channels to run wire along the edge of the floor and up posts and the back side of beams.  Your sip screws are already in so no danger of hitting a wire.  To get wires to receptacles and switches you can route a channel up the panel or over from a post.  Unless you are doing everything yourself I don't think you would save money doing wrap and strap.  When I built my house in NC I debated wrap and strap and to get enough foam (from Lowes)  to get a decent R value plus outside sheathing it was pretty close to the cost of a panel.  I've lived in 2 sip houses and you can't beat them for energy efficiency.  As far as getting electrical and plumbing any place other than near walls you can build up from the joists.  I put 2x4's on edge after putting a layer of 1" t&g over my 1st floor joists and then after my wiring and plumbing I put another layer of Advantec and then my finish floor.  I've actually done very few frames locally, most are away so I really don't know any plumbers or electricians.  You could check with Pete at High Country Timber Frames or Eric at Carolina Timber Works.  They do plenty of work in the area.  I'm getting sips for a 24x32 addition that I will be doing I will see what the cost was and that way you will have an idea if you want to go that route.  

[logman]

It was 15k with tax to do the 24x32.  Before the pandemic it would have been probably 10k.  That is for blank panels not precut.  

[Don P]

That must be General Panel;
General Panel Website

Eric was who I was thinking of asking too, I know they used Sweetwater here on a couple of jobs for plumbing but that has been a few years.

[logman]

Not to hijack the thread but a little story to show how small the world is.  When I got laid off from Carolina Timber Works when the economy crashed naturally I went and applied at the other timber frame companies.  I was talking to Pete at High Country and in my resume I had something about being on the USCG Glacier.  I left the ship right before the Glacier went on it's last Deep Freeze to Antarctica before decommissioning.  Pete came on TDY for the last cruise so he knows some of my old friends from the CG.  I thought that was a huge coincidence for a little town like Boone.

[Palmetto]

Since you are building near Boone don't discount sips.  I get mine usually from Johnson City, Tn.  Very close to Boone to cut down on shipping plus they have the best prices of any other sip manufacturer that I have found.  Using sips if you pad out the back side of the frame to slide t&g or sheetrock it gives you channels to run wire along the edge of the floor and up posts and the back side of beams.  Your sip screws are already in so no danger of hitting a wire.  To get wires to receptacles and switches you can route a channel up the panel or over from a post.  Unless you are doing everything yourself I don't think you would save money doing wrap and strap.  When I built my house in NC I debated wrap and strap and to get enough foam (from Lowes)  to get a decent R value plus outside sheathing it was pretty close to the cost of a panel.  I've lived in 2 sip houses and you can't beat them for energy efficiency.  As far as getting electrical and plumbing any place other than near walls you can build up from the joists.  I put 2x4's on edge after putting a layer of 1" t&g over my 1st floor joists and then after my wiring and plumbing I put another layer of Advantec and then my finish floor.  I've actually done very few frames locally, most are away so I really don't know any plumbers or electricians.  You could check with Pete at High Country Timber Frames or Eric at Carolina Timber Works.  They do plenty of work in the area.  I'm getting sips for a 24x32 addition that I will be doing I will see what the cost was and that way you will have an idea if you want to go that route.  

That's all great info.  My purpose for thinking about wrap-and-strap was, as you guessed, to save money.  I just figured SIPs would have a big installation cost, on top of the materials cost.  But, if it's really close to comparable, I definitely wouldn't rule it out.  Maybe SIP prices will go back down over the next year or two!

Thanks again!