Has anyone any experience using sensors to monitor performance of a retrofit or identify risky humidity in joist pockets or inside building fabric? I found this article from a US builder. Why We Need Building Sensors - Fine Homebuilding
I have found a a few products, OmniSense seems to have a big presence in the US. It is a whole system seems to need a quite expensive base station. There is also this kind of thing. Uses BLE so accessible locally using their APP. Might be an open stream. Not got too into it.
I think might be possible to interpret a WME from a RH value and RH sensors seem to be much cheaper and more available.
“A BRISTOLIAN’S GUIDE TO SOLID WALL INSULATION” recommends wrapping joist ends where they are embedded in a solid wall. Again, Ecological building systems, retrofit underfloor heating system recommends taping joint/wall junctions. It feels a little risky in a solid wall and so I plan to inject Boron Paste as a precaution but would like to do just a small area with monitoring in place and a backout plan should humidity be negatively effected over a long period.
The architect Harry Paticas did something similar in his own house but I have not seen enough detail on his monitoring method to confidently recreate.
Taping junctions is a well established practice. Even is the airtightness tape doesn’t breath it is such a thin strip that the fabric behind can breath ok.
The embedded timber is far more contentious and I would certainly want to monitor results.
The AECB used to have some details on systems. It may not any more and even if they do the details may well be out of date.
Hi Tim,
Appreciate info on tape. I also have decent enough voids around the joist ends so would need a lime parge before tape would be worth considering so I’m looking at a huge change to how air moves around there and the materials in contact with the joists. Not as simple an intervention as just adding tape.
I know in brick or block it isn’t that hard to fit an insulated ledger plate for joist ends to be hung from. I don’t believe it’s half as well recommended in solid stone wall where fixings are much harder to organise and you could easily compromise the tensioning force joist ends except making buckled walls a greater risk.
I posted the same Q on OpenEnergyMonitor, see if anyone had any equipment/methodology.
Someone responded with these two AECB links. Equipment is research grade. One retails for ÂŁ2000 in the UK but looks like the OmniSense system, might be a rebrand. OmniSense direct sell a pack with ten sensors runs to ÂŁ1200 with ÂŁ150 delivery. You could custom pack your own system for under ÂŁ100 delivered but its all pricey stuff.
https://aecb.net/wp-content/uploads/2024/11/IWImoisturepaper_Martel-et-al_2021-2.pdf
Ah yes, Tim Martel. I could almost have guessed. He is a very techy guy. He even wrote some add ons for PHPP.
Lime is pretty much a sterilising agent and also manages humidity. It seems like a very good idea to use it in proximity to timber. To meaningfully control the humidity though you would need more than just a parge. How about plastering? That would also help greatly with airtightness in the ceiling voids.
Walls in the room already plastered with Lime on Slate rubble jointed with lime. I could put on at a reasonable thickness but no need to finish.
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