If an old house is to be resided, and there is no house wrap or there is incompletely installed house wrap, so the owner wants any old house wrap removed to the extent possible, and new house wrap installed, but cannot afford to replace windows - even though they understand it would be best - what would the "siders" typically do with house wrap where it meets windows and doors to ensure water cannot leak behind house wrap or through windows or doors at the edges where house wrap meets doors and windows? Besides what is typically done, what would be advised to do? Is there a way to ensure there will likely be a durable, lasting (>30 years)sealed building envelope without replacing windows and doors? If so, can you please explain so I can ask siders to do this when rewrapping my house, since I cannot afford new windows? Can you please compare how rewrapping a house when windows are not being replaced, would compare with what occurs with new builds or with renovations where houses will be rewrapped and all windows also replaced?

  • House wrap is more water resistant than water proof. It is usually just cut around windows.
    – crip659
    Commented Oct 17, 2023 at 20:36

1 Answer 1


House wrap is not your main defense line against water intrusion or drafts. It is more like a secondary line of defense, in case any water goes past the siding, you have another layer there, directing the water down instead of soaking your sheathing.

So just tell the siding people to use a combination of wrap tape and window flashing tape (eg Butyl) when going around windows. If the siding and j-channels are installed correctly, the flashing tape should not see any water in the first place.

Assuming that your windows are not leaking water now, there is no advantage to replacing your windows in terms of water intrusion.

As for heating loss, it really depends on how old your windows are. There will be a huge difference between 100-year-old windows and new windows, but not so much between 20-year-old windows and new windows of the same quality. There can be a huge difference in efficiency between 20-year-old cheap windows and modern triple-pane windows. But the gains can be offset if you don't have an insulated attic, no insulation in the walls, a leaky rim joist, etc. Speak with an efficiency expert -- some utilities provide this service for free -- and not a window salesperson.

  • Is it typical or required for siding people to tape/flash around all windows when they install house wrap regardless if they are installing house wrap for the first time, or for some reason have to removing all house wrap and reinstalling it? I would think the cost of re-wrapping a house would include taping/flashing windows and doors - maybe a separate line item or just worked in to the total cost on an estimate. The reason I am asking is because before I considered residing/re-wrapping, I got an estimate to reflash/tape my foyer window which cost several thousand dollars.
    – Jessi
    Commented Oct 19, 2023 at 23:47
  • "Flashing" just means closing the gap between two materials so that water does not go in. Thus, when someone says "add flashing to a window" they could mean as much as removing the window and redoing the whole installation, or they could mean putting some cheap tape between the wrap and the window edge. It's all in the details. But yes, installing wrapping includes putting tape around openings (/windows).
    – Cheery
    Commented Oct 19, 2023 at 23:54
  • @Jessi The estimate seems very high, although I could imagine that reinstalling a very expensive, big foyer window in a building in NYC could easily cost that. But a single window in a house? Might as well install a new window.
    – Cheery
    Commented Oct 20, 2023 at 0:05
  • Cont..Estimate to fix leak @ foyer window included: break/remove a little siding, remove arch window molding, inspect sheathing but not cost to repair/replace if needed, tape/flash window, install new siding, window molding and J-channel. This estimate was before I was advised to re-side and re-wrap whole house. It now seems redundant that I'd pay for both to stop the leak around the foyer window since isn't EVERYTHING listed to attempt to stop leak already what would ordinarily have to be done when residing AND re-wrapping the entire house?
    – Jessi
    Commented Oct 20, 2023 at 0:07
  • Well, it depends on where the leak is coming from. The problem with water is that it travels. It could be a leak in your roof that is coming through the sheathing, but you only see it when it hits the window. Or it could be the window itself leaking. Or that water is getting through the trim, etc. So when one starts peeling things off looking for the source of the leak, it sometimes turns out to be a 1-hour job (eg adding some silicone), or a 1-week job. It's really hard to give an estimate. But an experienced handyman might be able to dig around and tell you.
    – Cheery
    Commented Oct 20, 2023 at 0:17

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