Sealing the sill
Our “final home” foundation has been poured and we are thinking ahead to when we air and water seal the Zip-R sheathing over the sill to the foundation. Our plan was to use Zip tape for this application, but unfortunately, the concrete forms that were used were brick pattern forms (as that’s all the subcontractor had). The brick pattern surface is covered with ridges and fake mortar lines, which will make air sealing difficult.
Are we best off trying to stick the Zip tape to the concrete the best we can, and then following up with a liquid flashing product to seal any remaining voids? Or would we be better off exclusively using a liquid flashing product (and no tape)?
Second, there are several kinds and thicknesses of EPDM to choose from to use for a sill seal. Plain black and white faced, as well as a variety of thicknesses. Does it matter which EPDM we use as a sill seal?
Thanks in advance!
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Replies
Nancy,
This appears to be a common problem for high performance builders. I would totally opt for a liquid flash as few tapes seem to stick to concrete well. For ultimate durability, you could opt for the liquid flash that requires mesh to bridge the gap.
If you opt for zip flashing, Huber recommends that you do not put the their liquid flash over their tape unless you use an "approved primer". You can put zip tape over zip liquid flash however.
I don't have any first hand experience with the EPDM gaskets but these seem to be popular:
http://www.conservationtechnology.com/building_gaskets.html
Nancy,
To air seal the crack between the foundation and the pressure-treated mudsill, I would use an EPDM gasket from Conservation Technology, or ordinary sill seal (flexible foam) plus caulk.
To air seal the crack between the Zip sheathing and the pressure-treated mudsill, I would use acoustical sealant, caulk, or construction adhesive (applied to the mudsill before the Zip sheathing is nailed to the framing).
This approach avoids the problem of trying to adhere tape to the brick pattern forms.
请注意，南希正在使用zip-r。如果您遵循马丁关于密封窗台的建议，请确保您使用的任何产品都与Zip-R中的泡沫兼容。有些人只是用它吃东西。我将在我自己的构建中使用Prosoco关节和接缝填充剂。再次，您必须检查兼容性。如果使用胶带，请使用录音机为胶带制成。许多高性能磁带都批准了可用的引物，这些引物用于OSB或粗糙混凝土等物品。这是一个小世界南希 - 我认为您正在从我租的地方建造一条街道！