John Sayers' Recording Studio Design Forum Archive

I finished the trench excavation for the sewer line. That was difficult work tunneling under the tree roots to try and save the large Cypress tree from harm. I installed the sewer line and made the connection to the main sewer line. The utility operator is supposed to come by tomorrow for the inspection. The general contractor will be coming in about two weeks to take over. I still have a few conduits to lay under the slab for the low voltage cabling and electrical entry into the room, some clean-up, backfill the trench, plenty to keep me busy.

Erik

Wow. Looks like that was an "interesting" job, to get that through! But at least it's done now, and you can move on to the next stage.

Progress is good!


- Stuart -

All of the plumbing and conduit is complete and now I am ready for the general contractor to come and prepare the slab and pour the concrete.

Erik

Steel delivery for the slab
Erik

Erik, I don't see any preparation for the pour yet: is that still coming? I'd expect to see gravel and/or sand as the base layer, well tamped (compacted), plus a vapor barrier membrane, before the steel goes in.

It's also common to form a footing around the edge of the slab, dug a bit deeper that the middle, to provide better support for the walls and roof... I'm hoping that all of the above will be coming soon, before the rebar and concrete go in?

- Stuart -

It happened so fast with the general contractor taking over. I received the shipment that morning as his crew had not arrived before the delivery... moisture barrier, steel, anchor bolts, stirrups, everything necessary was all there. I went to work and he texted me pictures as they were preparing the slab and I trust him on these matters. We had gone over my plans in detail that I prepared and posted previously. They call for grade beams around the perimeter and one internal. I am a licensed civil engineer so I should be capable of getting this part correct. You can see the grade beams excavated, moisture barrier installed, steel reinforcing being dowelled into the existing slab. I did not specify sand or gravel subgrade. It is typical for slabs of this size in this area to just compact the existing material. We do have expansive clays that can be an issue, but the material here was not too bad (as in fat clays), the slab is relatively small, and we have the grade beams. By the way, when I backfilled the conduit trenches and where the trees and roots had been removed by me a while ago, I compacted the soil back in lifts very thoroughly under optimum moisture content. Plus a few rain events water tamped the soil very well. I was very thorough about that and so they only had a few inches of fill to compact that was generated by the grade beam excavation. I did not mention any of that, but it is important to note.

My wife was there at home, they discovered an unknown irrigation line and broke it as they were excavating the grade beams, and called me to find the shut-off valve. My guess is the previous owner had plans to irrigate the area where the wooden deck was located and changed their mind. I excavated all over that place and never came across it. Erik

And so I got home and the slab was done.

I have a question about the window detail in Rod's book. It appears to be for interior windows and I need to make an exterior window. I can't quite figure out how to incorporate a window sill flashing or any other modifications for better weatherproofing which I am thinking I will need.

Erik

The framing crew arrived. I got very stressed out as I saw they were not understanding the plans correctly and the two leafs were being connected. After a meeting with the general contractor and the foreman of the framing crew, they started making corrections. Once it started looking more like the details in the plans they started to understand and make it right. Whew!

Erik

Double layer of 7/16 OSB going on exterior. First a vertical seam, then a horizontal seam on the second layer.

Erik

The framing crew brought up a good point. With two layers of weight on the inner leaf, the wall will want to lean over. I told them the first ceiling layer of OSB will prevent that and will have to go on first, then explained the staggering of layers.. ceiling, wall, ceiling, wall shown on the details in the plans. They put up some temporary blocks between the two framed wall leafs for now as shown in the picture. They will be removed later.

Erik

With two layers of weight on the inner leaf, the wall will want to lean over.

Why would it want to lean over? If built correctly, there should be no problem with that. It would only lean over if not set vertically and not well bolted to the floor. Also, if the layers are not put on correctly. And the ceiling framing will prevent any "leaning" from happening too. I'm not sure why they think the wall would lean...

- Stuart -

I am sure the concern is not necessary. The sole plates are anchored to the slab. I will make sure the blocks get removed. Not very much progress going on over the holidays. Met with the electrician and hvac subcontractors to go over any remaining issues with them.

Erik

Met with the electrician and hvac subcontractors to go over any remaining issues with them.

You might already be aware of this, but with the electrician did you make sure to specify star grounding, only one single wall penetration per room, and all surface-mount outlets, switches and light fixtures? If you don't specify that up front, you'll likely find the electrician punching holes in all your brand new walls, and poking wires and boxes through them...

Also, for the HVAC guy, did you specify that the the flow velocity from all registers must be less than 300 FPS at the absolute maximum, and ideally less than 100 FPS? And also that all duct work must be lined on the inside with proper duct-liner, the registers must be the special low noise (high open area) type, and give him the full specs for the silencer boxes? Here too, if you don't specify all that up-front then they'll just do the typical high velocity, small cross section, unlined ducts with no silencers and small, cheap registers.

I guess you already did, but it doesn't hurt to make sure!

Happy New Year!

- Stuart -

Yes, I specified the star grounding. He calls it isolation grounding, but we are saying the same thing. I actually ran a few extra conduits through the slab for no holes through the walls. The wiring from the new subpanel in the garage will go through a hole in the garage wall outside of the two leaf system, then run surface mounted outside the room to the conduits I placed, then through the conduits into the room and then all surface mounted electrical from there inside the room. However, I failed to properly plan for one thing. I am planning on mounting a tv for having sports on in the man cave when the need arises. The prime location for the tv is very far away from the conduits and the surface mounted electrical will look ridiculous getting over there. I wish I had set one more conduit, but I wasn't really thinking about the ideal location for the tv. Since this will be the furthest wall from my closest neighbor ( I know... doesn't matter), and there will be electrical in the bathroom behind these two leafs on that side, and there is a bathroom and a third wall on the other side of the bathroom (4 ft away from the two leafs... I know... is that a 3 leaf issue???? I guessed that the 4 feet distance is ok). I decided to allow one hole in that wall. I purchased the putty packs for the box. Make it two holes because I need the coaxial cable for the tv as well. It is a bit of a compromise on the isolation, but I was preparing to have a few uh oh moments.

The A/C system will be the mini-split ductless system. I ran a 2 inch conduit through the slab to get the line set and control wire from the outside unit to the inside unit without a hole through the wall. I will have the necessary fresh air ventilation unit mounted in the garage and will then have two holes for the air exchange into the room. I will draw fresh air from the outside through a garage wall and build silencer boxes in the garage for the ducting. The flow rate on the ERV unit is only 78 cfm. I ran a 3/4" conduit from the garage into the room for the control wire for the ventilation unit to mount the controller in the room without a hole through the walls. I originally asked my wife if she wanted a/c in the bathroom as well. So, I added a second indoor unit in the bathroom and exhausted the air from the ERV into the existing room in the garage that will serve as an entry room (or maybe one day an isolation room or control booth ... dreaming). However, I did not plan properly. The HVAC guy said he can only get one line set through the 2 inch conduit because of the insulation around the line set. So, the second indoor unit line set will have to be surface mounted on the outside of the room up through the soffit vent space above the two ceiling leafs, through the attic space over to the bathroom. Problem solved. The HVAC guy said the indoor unit for the bathroom was overkill which I knew. He suggested we just exhaust from the ERV into the bathroom and it will keep the bathroom plenty cool. We can save the cost of the additional indoor unit. I am waiting on the cost reduction amount to make the decision. The HVAC guy also happened to be very interested in noise reduction and said he has a very expensive high quality sound meter and wants to come back and measure the sound reduction of the room when it is finished. I also set a 3/4 inch pvc line though the slab for the condensation drain for the indoor unit. However, when the crew poured the slab, they knocked it over and it is now buried in the slab. So, the HVAC guy will have to put one hole through the walls for the condensation drain line. I plan on building a bass trap in that corner that will cover the line set and condensation line and hopefully reduce the sound transmission into the pipe and out of the room.

Thanks for keeping a set of eyes on this for me Stuart and a Happy New Year to you as well. Pictures to follow to help explain, and let me know if I am heading wrong somewhere.

Erik