Replies

1. GBA Editor
   Martin Holladay | Apr 17, 2017 05:02pm | #1

   Grey Wolf,
   Conservation Technology's EPDM sill seal is a quality product. I haven't used a neoprene sill seal, but I imagine it will work.

   In many cases, it's helpful to caulk the crack between the mudsill and the foundation after the framing work is complete (since the framing adds weight that compresses the sill seal). Combining sill seal and caulk is a belt-and-suspenders approach.

   -- Martin Holladay

2. 
   GreyWolf92 | Apr 17, 2017 05:43pm | #2

   Thanks Martin. What do you think about high performance tape, instead of caulk over the crack? I've been told this is best practice. Although, I'm sure opinions vary!

3. GBA Editor
   Martin Holladay | Apr 17, 2017 05:56pm | #3

   Grey Wolf,
   It sounded from your original question that you were pinching pennies. Why else would you avoid EPDM sill seal?

   If you have a decent budget, Siga Wigluv tape is an excellent way to seal the crack between your mudsill and your foundation.

   -- Martin Holladay

4. 
   GreyWolf92 | Apr 17, 2017 06:01pm | #4

   My post was primarily because EPDM will take too long to arrive AND I don't think the air seal edges are needed since I will be using tape. Neoprene I can buy today.

   The primary reason for using them is for a thermal break between metal and wood.

   I was planning on using pro clima tescon because it is more vapor open.

   According to your tape test, seems to stick as well? But just is easier to rip?

5. GBA Editor
   Martin Holladay | Apr 18, 2017 06:21am | #5

   Grey Wolf,
   You are overthinking this. It sounds like you want to tape the crack between your steel trailer and the first wooden components of your tiny house. If that's what you are doing, why does the vapor permeance of the tape even matter?

   The point of the tape is to seal air leaks. It's not as if your steel components are vapor-permeable -- so why does the tape have to be?

   -- Martin Holladay

6. 
   GreyWolf92 | Apr 18, 2017 01:54pm | #6

   For the rest of the plywood seams, I would favor a more vapor open to facilitate better drying. For the bottom plate, yea good point.

   I am purchasing a package from Pro Clima, so will have the Tescon Vana tape. Planning on using that unless there is any reason not to.

1. 
   Paulmcgee | May 25, 2019 05:03pm | #7

   What if the exterior WRB like Blueskin vp100 SA is run down past the rim joist/plate and adhered to the concrete or icf ? do we need to worry how air tight the sill gasket is?

1. Expert Member
   MALCOLM TAYLOR | May 26, 2019 12:18pm | #8

   Paul,

   if your air-barrier is at the sheathing, and you can effectively seal it to the concrete foundation wall, all you need is a sill-sealer to isolate the concrete from the wood sill above.

1. 
   Deleted | May 29, 2019 10:43am | #9

   Deleted

7. 
   NotYourFwiendGuy | Jul 10, 2020 07:09pm | #10

   Hi, I'm just adding update for considering a fancy European SIGA tape to seal the sill to concrete on exterior side. I spoke to someone at SIGA, and they now recommends their FENTRIM F tape for this purpose over WIGLUV. It comes in 6" and 9" widths, with split tape which is nice. They first sold it in black color (has a felt texture on the face), but now it appears like the updated it to grey color, which will blend in nicely with concrete if it is visible below the first course of siding/skirt. (though it's not rated for any UV exposure) I applied Fentrim about 1.5 years ago very close to the ground and nowhere has the tape edge even slightly pulled away from the concrete nor wood (Zip or PT depending how I lapped it). Seems like a great product.