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1 Answer

Rigid Foam on Flat Roof that Terminates to Mansard

I have a flat / Mansard roof. There is an addition to the back of the house that is the same roof type as the original two roof levels. The add-on roof is leaking. It has 3 leaking skylights that I plan to remove. The sheathing is very spongy. I plan to replace the sheathing and to use 3 layers of 2.5 inch polyiso rigid foam above the sheathing.
I only plan to work on the add-on roof for now. My plan is as follows:
1) remove / replace all old decking and any structural members that are rotten

Asked By KALETA HILLIER | Aug 12 16
6 Answers

Subfloor cavity question: Method in the madness?

Just posted this morning about a bathroom remodel I'm doing. Got some great feedback. Thanks much. Now I've encountered a different problem, and I didn't know if I should tack it on to my previous question or just post separately. I've obviously opted for the latter.

Asked By Doug Waugh | Aug 4 16
15 Answers

Hybrid cut-and-cobble foam board with batts in upstairs bathroom exterior walls?

I have a house in Columbus, Ohio (Zone 5) that was built in the early 70s, and I'm in the throes of a complete upstairs bathroom remodel. I've gutted the space down to studs (even replaced the subfloor), but I've opted to keep the cast iron tub. Well, I'm ready to insulate, but as I read the Q&A exchanges on this site (and several others), I realize that my options are limited. The original insulation schematic included black fiber board sheathing on exterior, unfaced fiberglass batts between 2x4 studs, and a 4mm layer of plastic as a vapor barrier over the whole thing.

Asked By Doug Waugh | Aug 4 16
8 Answers

Can I drain my furnace's condensate line into the sealed sump pit?

Some background:

- Radon remediation system in place in the basement (usual sub-slab depressurization).
- Sump pit covered with plexiglass and sealed.
- Basement slab perimeter has drainage channel that wasn't filled in by the radon folks (I gather not optimal).
- We are planning to replace the 80% efficient furnace in our unconditioned attic with a high efficiency unit since we are planning to condition the attic using a "flash and batt" approach.

Asked By Rob Moore | Aug 9 16
2 Answers

HRV delivering treated air directly to the ASHP air handler air intake which distributes cool or warm air through ducts

Has anyone tried this? The baths and kitchen would have dedicated exhaust fans.
This would in net-zero homes.

Asked By susan cosentini | Aug 7 16
4 Answers

Minisplit ducting options for retrofitting two small adjacent rooms

My home in Zone 2B has an approximately 500 square foot addition that was added to its north side many years ago. Like the rest of the 1950s era house, it is built of concrete block, with single-pane metal windows and (amazing to me) a flat roof where the space above the celing/between the joists is vented rather than insulated. Unlike the rest of the house, it is not served by the central HVAC system.

Asked By Nickolas Van Kleeck | Jul 31 16
13 Answers

Minisplit retrofit in Climate Zone 2

I'm trying to figure out how to use a minisplit system on a retrofit project. I got a quote from an HVAC company (recommended by the equipment rep), but some of their opinions don't make sense...which brings me here today.

The HVAC company proposed 4 zones with a 3 Ton compressor outside:
1 ducted 9k unit in attic, serving Guest Bath, Guest Bed, and Office
1 ducted 9k unit in attic serving Master Bed and Bath
1 9k ductless serving kitchen
1 9k ductless serving living

Asked By Green Heron | Jul 26 16
2 Answers

Has anyone used a WhisperComfort Spot ERV ventilator (FV-04VE1) in a high-performance home?

Will this inexpensive, simple-to-install Panasonic energy-recovery ventilator work, placed in a central location of a 1500 s.f. house -- mostly ceiling on the second floor with 1-1/2" bedroom door undercuts and the Whisper Green motion-sensor-activated bath exhaust fans? Or is that delusional?

I am in Zone 6. Thanks.

Asked By Susan Cosentini | Jul 30 16
10 Answers

Choose Slightly Higher HSPF or save $ upfront as payoff is ~7 years.

I'm looking to buy a mini-split for my business office. Seems simple enough but I have 3 basic choices.
15 SEER 9 HSPF at base price for either 115v/230v, simple inverter
21.5 SEER 9.8 HSPF(IV) bp+$300 for 230v, upgraded inverter
21.5 SEER 11.2 HSPF(IV) bp+$320 for 115v, upgraded inverter
I've no problem installing 230v vs 115v and it's only 5' from the panel.

First, is it even worth paying the $300+ for about a $40/year savings? 9 vs 9.8 or 11.2,

Asked By Karl Koning | Jul 27 16
1 Answer

Fiberglass batts in a cathedral ceiling — Round 2

Thanks, Martin and Dana, for your timely responses and comments [in a previous Q&A thread called “Fiberglass batts in a cathedral ceiling?”].

My wife and I read the articles, "How to build an Insulated Cathedral Ceiling" and "Site-Built Ventilation Baffles for Roofs." The air-sealing of the site-built baffles sounded formidable and the mention of no known failures from the use of impermeable baffle materials was enough for us to consider using them.

Asked By Michael Watson | Jul 27 16
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