Jump to content
Sign in to follow this  
randynavarro

How Would You Dry This House Out?

Recommended Posts

This home is situated in a suburb of Seattle built post WWII. The homes are very simple boxes sitting on slabs and constructed of concrete block.

Almost everyone of these homes I've inspected has moisture troubles from the slab and walls leaching too much moisture which ends up in mold and moisture problems at the interior.

I have a buyer who is ready to do a rehab. project on this particular home.

http://www.redfin.com/WA/Mountlake-Terr ... me/2742560

It's easy to see in the photos some of the mold growth and damaged and removed drywall.

I have some ideas on how to get this home dry but wanted to throw it out to y'all to get some other thoughts and ideas.

Whaddya think?

Share this post


Link to post
Share on other sites

Been sitting empty with the AC off for long?

Might be worthwhile if the AC can be maintained in optimum condition, is installed properly and if adequate make-up air equipment is present.

Moisture issue should be easily remedied on such a simple and small house

I think you and I both reside in a zone 2 environment.

Marc

Share this post


Link to post
Share on other sites

Should be easy to lower the interior humidity by ventilating. It would be a very easy HRV install, or you could use a quiet inline bath fan on a timer switch. That's a small house, so occupant load could vary wildly--one person who has a f/t job and some outside activities is one thing, a family of four with three dogs and a fishtank is another.

I'm assuming that whatever drainage can be done has been done.

Share this post


Link to post
Share on other sites

Been sitting empty with the AC off for long?

Might be worthwhile if the AC can be maintained in optimum condition, is installed properly and if adequate make-up air equipment is present.

Moisture issue should be easily remedied on such a simple and small house

I think you and I both reside in a zone 2 environment.

Marc

That's so cute.

Marc, AC around here is when you open a window. AC systems are scarcer here than hen's teeth.

Randy,

Why, after 50 years is there suddenly a mold problem? I've had a couple of dozen of those where the pipes were dripping where they come of through the slab inside the interior wall between the kitchen and bath. I'd suspect a broken pipe before I suspected rising damp was the cause.

If I bought one to rehab it, I'd build in multi-echelon defenses. I'd bust out the slab and pull out all of the original pipe from the street and then re-plumb everything from meter to fixtures with PEX. I'd patch that slab very carefully using a sleeve around where the pipes enter so I can seal them separately with hydraulic cement. I'd then wrap the perimeter of the slab with a Multi-flow collector system drained to a deep drywell somewhere on the property as far downhill and away from the house as I could put it. I'd probably install a second echlon six feet out from the foundation to keep the nearby yard as dry as I could and then replace the first course of block with a damp course. Follow that up with a Delta rainscreen membrane behind any siding and I think I'd have a nice dry little house.

ONE TEAM - ONE FIGHT!!!

Mike

Share this post


Link to post
Share on other sites

One thing I would look for in my cold clammy climate is a heat source in every room. In my area, that would likely be electric baseboard heaters, cheap and easy to install, but there needs to be at least 100 amps at the panel. The wall mounted fan heaters are better, but cost a bit more.

Is there any insulation in those walls? If not, pump some in and add some in the ceiling. Make sure the attic has ventilation.

Like Mike says, fix the leaky plumbing in the slab.

Or could you just abandon that old stuff and run a new line up and in through the wall?

Here's some other ideas:

Install a gutter on the back of that roof. [:)]

Direct the downspouts away, preferably adding a buried drain when time allows.

Best to do what Mike says and replace all the drainage but they could have the perimeter drains around the slab inspected, and possibly cleaned and repaired. They are most likely concrete or clay tiles, clogged with crud, but sometimes the mud can be blown out of sections of them and then a new line to the storm drain can get drainage flowing again. If it was me, I'd just start digging up sections and replacing till it was all new.

Share this post


Link to post
Share on other sites

I don't think the 'mold' looks all that bad, could be just from sitting empty. I think $94 grand is a hell of a lot of money for it, around here that would be $40 tops, closer to $25 out in the boonies.

If it were mine I'd start by gutting it. Fix the plumbing as Mike said, then after all the wiring and heating is done; I'd lay 1" EPS on the floor covered with 1/2 OSB screwed to the slab (no need to remove the asbestos floor tiles), use 1 1/2" Dow Wallmate on the walls, and spray foam the roof deck and gable ends making certain the block cores are sealed at the top (they're either full of vermiculite or they're hollow and will generate stack effect contributing to ice dams). An 80 cfm bath fan will be plenty big enough to handle the moisture load, at 5000 cubic feet that's 2.6 air turns an hour. Everything outside is toast; the chimney needs pointing, the flashing is a mess, the roof cover needs to be mowed, and what's left of the gutters is a joke. I'd add overhangs before resurfacing the roof, and in my climate would cover the walls with Wallmate, Tyvek, and siding (maybe fiber cement, but I really like the look of NuCedar cellular vinyl) after touching up any block issues.

Even with access to all of those building materials at wholesale, it'd be hard to do all that with the asking price as the budget. It will never be worth $300/SF.

Share this post


Link to post
Share on other sites

Randy,

I think you should put in a radon mitigation system.

I was at a ventilation conference in Wisconsin a few years ago and the instructor had some pretty impressive stories about how sub-slab radon mitigation systems helped cure moisture problems in basements.

I like this idea better than dehumidification or an HRV because it's attacking the problem at its source rather than letting moisture get into the house and dealing with it there. Source control is always the way to go if it's possible.

Good luck.

Share this post


Link to post
Share on other sites

Where are you finding excessive radon?

Average working levels around here are pretty low. Not that you can't pull a number, but working levels are low.

At least, that's been the result of my tests. We pull spikes from time to time, but on all the houses where I've actually been able to do real testing, the working levels are marginal.

Share this post


Link to post
Share on other sites

Remember that a radon system doesn't just take out radon. It also takes out other nasty soil gases and excess moisture from under the slab.

You don't have to have radon to benefit from the technology.

Share this post


Link to post
Share on other sites

The only hot spots for radon in Washington State are Spokane - a five hour drive east - and Vancouver - a three and a half hour drive south of that house.

ONE TEAM - ONE FIGHT!!!

Mike

Share this post


Link to post
Share on other sites

The only hot spots for radon in Washington State are Spokane - a five hour drive east - and Vancouver - a three and a half hour drive south of that house.

That's what we used to think about Oregon until someone started to do a whole bunch of radon tests. The radon "maps" are worthless. If you want to know whether or not you've got high radon levels, you've got to test for it.

Whether or not you *should* want to know whether or not you have radon is a different matter.

- Jim Katen, Oregon

Share this post


Link to post
Share on other sites

From the sounds of it, we could have a cloud of Japanese radon coming our way soon.

From what I've read, radon originates from uranium deposits, so it would occur in scattered locations just about anywhere.

Share this post


Link to post
Share on other sites

From the sounds of it, we could have a cloud of Japanese radon coming our way soon.

From what I've read, radon originates from uranium deposits, so it would occur in scattered locations just about anywhere.

Yeah,

It is just about everywhere but it's only a concern where it's "hot" - in other words, where the radiation it gives off is over what they consider to be a safe threshold.

A while back I thought about adding radon to my list of services, because when out-of-state folks move out here they keep asking for radon testing and seem to think that I'm lying to them when I tell them it's not worth bothering with.

Anyway, I got on the phone and tracked down the Washington State radon guy. Turns out there is only one person employed in this state as an expert on radiation; he's an ex-submariner. The poor guy must have an office cubbyhole somewhere in the deepest darkest recess of the deepest darkest basement in Olympia because he seem to be starving for someone to talk to about what he does and he spent about 45 minutes on the phone.

Maybe he's wrong or full of it up to his eye sockets, but he seemed to be very knowledgeable about the whole topic and sounded pretty confident in his answers.

ONE TEAM - ONE FIGHT!!!

Mike

Share this post


Link to post
Share on other sites

Where are you finding excessive radon?

Average working levels around here are pretty low. Not that you can't pull a number, but working levels are low.

At least, that's been the result of my tests. We pull spikes from time to time, but on all the houses where I've actually been able to do real testing, the working levels are marginal.

Kurt, even in Oak Park in the last year I've heard more regularly of elevated radon levels. Nothing crazy -- in the 4-8 range -- but still above the recommended action level. And I work out in the western suburbs regularly, where it's even more of a problem. From my experience, radon is not much of a problem in Chicago proper but becomes more of an issue the farther away you get. Where are you testing mostly?

Share this post


Link to post
Share on other sites

Sometimes I will suggest a radon system to help control soil gasses and evaporative moisture. I have seen folks tap into the concrete block foundation, install an inline fan to help dry foundation walls. I was surprised but that actually worked pretty well.

Remember that a radon system doesn't just take out radon. It also takes out other nasty soil gases and excess moisture from under the slab.

You don't have to have radon to benefit from the technology.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...