Encapsulate a crawl space,New ductwork, rotting floor joists…

[Charlsi Kelley]

Hi BP! I am under contract on a property that has numbers potentially good enough for a brrr. We are under contract at 300k and ARV is 430 bast on very similar comps in neighborhood. I had a budget of 30k rehab to do the necessary updates to get to my 435k target ARV. Hone is in excellent shape - new roof, floors are perfect- just a time capsule from the 80s. However, the property has 4-6 rotting floor joists and needs new subfloor in some sections. The cause is apparently long-term moisture damage from the ductwork that runs in the craw space rather than the attic. Yes we are going to push for a price reduction but in your experience should I do all of these repairs all at once before tenants move in? Should I do them in stages after I can save up some cash flow/refinance? I don't believe any of these will add to the value of the ARV:

1. Replace joists, subfloor (appx 14k)

2. New ductwork (8k)

3. Encapsulate crawl space (8k)

[Marcus Auerbach]

You are correct, no impact on the ARV, but the quotes seem exuberant. Lumber prices are still elevated, but 14k for 5 floor joists?? You'll need some new OSB as well, so I would say a grand in material including supplies and probably 3 days or work for two carpenters. Thats about 5k in total and the rest is pure profit. Similar for 2 and 3

[Jon Spisak]

Charles, My recommendation would be to get it all done now. It would be hard to remove subfloor and repair floor joist with your tenant occupying the residence. I would definitely have a mold inspection done. Based off of what you stated i.e. crawl space, moisture, duct work, new sub floor. I would have a thorough mold and air quality test done.

[Kris L.]

@Charlsi Kelley

You would definitely want to do 1 and 2 and the same time at a minimum. I doubt a bank would be keen on a refi with issue 1 anyways. I do agree with those costs seeming high. Get at least 3-4 quotes for this. My flip has a very similar issue to item 1 (caused by bad plumbing in this case) and the repair was quoted at half your price and included replacing a foundational beam as well.

[Charlsi Kelley]

@Marcus Auerbach I agree I wasn’t expecting this price tag either I just had the first quote and this was from more of a residential service business -I’m sure with high marketing costs passed on to traditional homeowner customers. I will shop around thanks for your input!

[Charlsi Kelley]

@Jon Spisak I agree getting it all done while the property is vacant is ideal. The floors throughout the home are solid hardwoods in perfect condition so I’m having everything replaced from below so we don’t have to rip up the floor I am sure that is adding to the cost

[Charlsi Kelley]

@Kris L. Thanks kris!! Hopefully you were still able to make a nice profit on your flip?! Do you remember what type of company/contractor you used? I have a quote from an HVAC company for the ductwork and a foundation company for the joists/subfloors but thinking those “specialists” probably charge a premium.

[Victor S.]

why not just fix the current ductwork? re: moisture damage. were the pipes sweating that much to cause such extensive damage or what is the alleged cause of "moisture" from the ductwork? i would get several more quotes in, preferably from people who fix stuff, not up-sell you on stuff you might not need. i would make sure the crawl space is/stays dry then assess what the best course of action is. since you'll have tenants in there, i doubt they care where their air is coming from (floor or ceiling). why waste $16k if other options could be available? #1 repair also seems high, so def. shop around some more.

[Dave E.]

@Charlsi Kelley I’ve been a contractor for over 24 years and I am a little confused by your post. Can you please explain how having ductwork in the crawl has caused such significant damage? That is very strange to me and sounds like something else may be going on? I’m not trying to be critical, just want to help and make sure the problem is actually getting solved for you!

[Genny Li]

You can't replace subfloor from underneath. Sister some joists, sure.  And I would rather sister than replace wherever I can.  Not subfloor. I'd be inclined to hack some reinforcement, unless the subfloor is crumbling. I'd replace the subfloor when the floor is next replaced. And I'd budget $1000 for the whole thing. 

Is it caused by uninsulated ductwork sweating in the summer? That's the only thing I can think of. So you'll encapsulate and condition the crawlspace, like Building Science (the site) recommends?  If you properly insulate and encapsulate the crawlspace and make it conditioned spaces, as you really should,.you shouldn't need to replace ductwork. That would solve the condensation issue. 

[Charlsi Kelley]

@Dave E. I appreciate your input! The general inspector thought the moisture damage was due to the ductwork under the house sweating and the home doesn’t breathe enough. Over time the condensation has caused the wood to rot. There was also some mold growth. I should mention we are in South Carolina so I am sure that heavy rains/ high humidity has contributed over time as well.

[Charlsi Kelley]

@Victor S. The ductwork is about 20-30 years old and both the inspector and the foundation company said the condensation from the ductwork lead to the damage over time. I don’t think there would be an alternative to replacing the ductwork. The subfloor is rotted through in some areas so it will definitely need to be replaced in those spots. I can probably get away with only replacing the worst if the joists- or at least sistering them for now- Is that the correct term lol!?

[Dave E.]

@Charlsi Kelley

Is the ductwork in contact with the rotting wood? Generally the ductwork is hung below or in between the joists. If it does condensate, then it drips down to the ground, not over to the wood? It seems strange to me that wood above the ductwork could pick up enough moisture to rot, unless the duct was in direct contact with it or dripping water on it. Water always flows downhill (except under very specific conditions).

Is the rotten wood under a kitchen or bath, or near an exterior wall?

[Victor S.]

Originally posted by @Charlsi Kelley:

@Victor S. The ductwork is about 20-30 years old and both the inspector and the foundation company said the condensation from the ductwork lead to the damage over time. I don’t think there would be an alternative to replacing the ductwork. The subfloor is rotted through in some areas so it will definitely need to be replaced in those spots. I can probably get away with only replacing the worst if the joists- or at least sistering them for now- Is that the correct term lol!?

 is the ductwork itself rotted out and leaking air? like the poster above me noted, how did the condensation from the ductwork damage the joists and wood above it? 

[Colleen F.]

@Charlsi Kelley  any asbestos in the duct work?  The me the sistering and subfloor replacement can't be done without ripping up some floor. Talk about that option with your contractors because I suspect doing it from above will be cheaper. 

[Charlsi Kelley]

@Dave E. From the inspection report:

“Staining on the crawlspace walls and evidence of lign to heavy microbial growth on the wood framing indicates that the crawlspace experiences periods of seasonal moisture increases. Lack of ventilation allows for the moisture to build. If left unchecked wood destroying fungi will promote deterioration of the wood floor system. I recommend review of the crawl space by a qualified crawl space moisture control specialist” “Several areas of damage / deterioration noted to the floor framing from moisture problems. (Lack of proMENU crawl space ventilation caused by the HVAC duct work ) The area is heavily stained with some deterioration noted on the sub flooring and floor joist. I recommend the ductwork removed from the crawl space and repairs completed. I recommend the HVAC moved to the attic.”

[Dave E.]

@Charlsi Kelley

So definitely use the inspection report to your advantage in negotiating the price as you have mentioned.

I don’t see a need to move the ductwork to the attic. That just seems silly to me. Sounds like the crawl is just poorly ventilated. Crawl spaces usually have vents for air flow. Just make sure that the vents are not obstructed or covered up. If they are it’s a pretty cheap fix.

It also doesn’t sound like the joists and subfloor are damaged to the point of needing replacement. Hard to tell, but from the description there is just some staining. Dig at them with a screw driver tip. If the screw driver easily pushes into the wood, then they need to be replaced. If they feel solid, then they are probably fine.

Install a dehumidifier in the crawl. It will pull humidity from the air down there and help keep some air moving which will help dry it out as well.

You may want to make sure the joints in the duct are sealed so that air doesn’t “leak” into the crawl space. This is pretty easy to do if you don’t mind crawling around. You just have to clean the ductwork at the joints to get the dust off, then you can wrap it in foil tape, or there is a sticky duct sealer that you basically can paint on. Once it is dry it seals the joints up.

Hope that is helpful. Feel free to DM me anytime.

[Genny Li]

Originally posted by @Charlsi Kelley:

@Dave E. From the inspection report:

“Staining on the crawlspace walls and evidence of lign to heavy microbial growth on the wood framing indicates that the crawlspace experiences periods of seasonal moisture increases. Lack of ventilation allows for the moisture to build. If left unchecked wood destroying fungi will promote deterioration of the wood floor system. I recommend review of the crawl space by a qualified crawl space moisture control specialist” “Several areas of damage / deterioration noted to the floor framing from moisture problems. (Lack of proMENU crawl space ventilation caused by the HVAC duct work ) The area is heavily stained with some deterioration noted on the sub flooring and floor joist. I recommend the ductwork removed from the crawl space and repairs completed. I recommend the HVAC moved to the attic.”

 That is a staggeringly stupid recommendation and a very expensive one. Condition the crawlspace. That entirely solves the moisture issue. It is also even more staggeringly moronic to claim it is LACK of crawlspace ventilation. Condensation is rather caused by the warm ventilated outside air coming in contact with the cold ductwork. How did this monkey pass any inspection qualification?????

Repair from underneath.  If the floor is solid, you can ignore the subfloor until you rip out the current flooring. If it's not, the flooring is going to have to go. 

[Dave E.]

@Genny Li

Hmm, that was a very aggressive response. Moist air in a crawl space can be very easily solved with some basic ventilation. That is a very different issue than having ductwork with cold air blowing through it. The condensation on the ductwork did not cause the problem. Having a damp crawl space did. Conditioning a crawl space that is not properly insulated will not solve the problem. It may actually make it worse. There are a lot of factors in getting this right, but I agree that the recommendations from the inspection report don’t seem to make sense. I will also admit that we are all making educated guesses as none of us have actually been in the crawl space.

[Kris L.]

@Charlsi Kelley

Mine was from a foundation specialist. For the duct work, were they relocating or replacing your air handler as part of that quote, or do you have a multi story building?

[Charlsi Kelley]

@Dave E. Thanks so much for your thoughtful response! While the idea of crawling around under there with a flashlight doesn’t exactly excite me, I would like to see it for myself. Perhaps our contractor can work with me to come up with a more affordable solution like you suggested. I will keep you posted on how things develop and appreciate your help!

[Charlsi Kelley]

@Kris L. Nope that was just for new ductwork!

[Mark P Grimes]

I agree with @Dave E. and @Genny Li definitely do not pay to have your HVAC ducts relocated to the attic. In the summertime in South Carolina your outside humidity will be high. If you put a humidistat in your crawl space in August and measured the humidity levels they could easily be over 90%. This is what is causing the moisture damage and mold. Best solution is to encapsulate and insulate (the walls) of the crawl space. Then either use a dehumidifier especially for crawl spaces or dump some conditioned air from the ducts into the crawl space. This will dry out your crawl space. We had the same issue here in Tennessee and my humidity levels were at 99% in the summer before encapsulating the crawl space and dumping some conditioned air into the crawl space. Now it never exceeds 50%. One word of caution is to check the radon levels after encapsulation to make sure they are in an acceptable level.

If you want to get into the weeds of crawl spaces and their problems here is a good article:

https://www.greenbuildingadvisor.com/article/new-vented-crawl-spaces-should-be-illegal

[Genny Li]

Originally posted by @Dave E.:

@Genny Li

Hmm, that was a very aggressive response. Moist air in a crawl space can be very easily solved with some basic ventilation. That is a very different issue than having ductwork with cold air blowing through it. The condensation on the ductwork did not cause the problem. Having a damp crawl space did. Conditioning a crawl space that is not properly insulated will not solve the problem. It may actually make it worse. There are a lot of factors in getting this right, but I agree that the recommendations from the inspection report don’t seem to make sense. I will also admit that we are all making educated guesses as none of us have actually been in the crawl space.

 It's aggressive because the guy is an INSPECTOR. I don't expect regular folks to know this, but he is diagnosing problems wrong and giving a "solution" that would make things worse.  He should not have a job, period.

He stated flatly that is was, indeed, caused by condensation on the ducts, and he could see it on his report.

Let's go back to the fun thermodynamic steam tables to explain relative humidity....

So, imagine that you are pouring a big cup of icy water.  It is the winter time, and it is 15F outside, and you are inside.  That cup will get very little to no condensation on it.  Why is that?  Because the warm air inside is very dry.  Except for what you add to the air from cooking, bathing, etc., the air can only hold in it as much water as it can hold at 15F, which is colder than the glass, so without human water additions to the air inside, you actually wouldn't get any condensation on the glass at all.  Not even a bead.  Because that glass is 32F.

So, imagine that you are doing the same thing, but it's in the middle of summer.  At first, you're inside.  In air conditioning, the air is squeezed, which makes it hot (P1/T1=P2/T2), and then the heat is taken away by a fluid that is cooler than this super hot air, and then the pressure is released, which by the same law makes it cold.  When this happens, the cold air dumps all the moisture it can't hold anymore--it is at 100% humidity at it's really cold temperature. But it's mixed with room air to a slightly warmer temp, so then the humidity drops into a more tolerable range, say 60%.  So 60% relative humidity at 74F is a lot more water than 100% RH at 32F.  That is, the dewpoint would be reached before you get down to 32F, and the water would begin condensing on your glass.

Now, take that SAME GLASS to a "well ventilated" area--your porch.  It's 94 degrees out there, and the RH is again at 60%.  Guess what? You glass is now streaming water.  Why?  Because the amount of water that is held in the 94 degree air is much, much higher than the amount held in the 74 degree air.

When you see that condensation is the issue, with wet, warm outside air hitting cold vents, to recommend "more ventilation" is to recommend "please, let's rot your entire house because I don't know my job."

Oh, and now let's move those same ducts to a ventilated attic!!!  MAOR ventilation with the same ducts!!!!  What happens?  It's raining inside when it's not raining outside.  If you're lucky and the attic is brutally hot, the ducts will have a harder time cooling the air down enough, so you'll have less condensation than in your "well ventilated" crawlspace, but that's still not a good bet to take.

It is one thing to see regular joe schmoes not understand this, but it is absolutely infuriating to see that inspector gave literally the opposite of the correct diagnoses.

You can choose to waste obscene amounts of money moving all your ductwork.  But what solves it is either 1) the correct conditioning of either the attic or the crawlspace or 2) lots of insulation around the ducts.  More ventilation without well insulated ducts just introduces even more water!

Now, let's look at an alternative, where the ductwork isn't the problem (even though the inspector literally said it was).  Let's vent a crawlspace better.  And let's have no insulation under the floors, because why have no insulation under floors?  Now you've made your whole FLOOR an ice-filled glass relative to the outdoors, and you're depending on essentially using a fan that blows enough to dry it out each night when the RH dips to keep from rotting out your subfloors.

Why don't we, instead, understand that the outside needs to stay outside and the inside inside and install a proper thermal and vapor barrier....somewhere?  I don't care if you decide to install it against the floor joists and then ventilate the crawlspace or you encapsulate and condition the crawlspace.  We need to have the outside be outside and the inside be inside, and none of this "let's play around and make some spaces that are both inside and outside at the same time."  Where is your thermal barrier?  Put things that are going to be colder than the outside in the summer inside that thermal barrier.

You can pick up a super, duper cheap relative humidity tester and see if there are actually moisture problems (meaning excess moisture being introduced) in your crawlspace pretty trivially.  If the difference in humidity percentage is exactly what you'd expect in the difference in temperature, then you don't have a "humidity problem" at all, because you don't have any moisture that is coming in from anywhere but rather have only the moisture that was already in the air before it cooled down.  You have instead a thermal control problem.

[Genny Li]

Originally posted by @Mark P Grimes:

I agree with @Dave E. and @Genny Li definitely do not pay to have your HVAC ducts relocated to the attic. In the summertime in South Carolina your outside humidity will be high. If you put a humidistat in your crawl space in August and measured the humidity levels they could easily be over 90%. This is what is causing the moisture damage and mold. Best solution is to encapsulate and insulate (the walls) of the crawl space. Then either use a dehumidifier especially for crawl spaces or dump some conditioned air from the ducts into the crawl space. This will dry out your crawl space. We had the same issue here in Tennessee and my humidity levels were at 99% in the summer before encapsulating the crawl space and dumping some conditioned air into the crawl space. Now it never exceeds 50%. One word of caution is to check the radon levels after encapsulation to make sure they are in an acceptable level.

If you want to get into the weeds of crawl spaces and their problems here is a good article:

https://www.greenbuildingadvisor.com/article/new-vented-crawl-spaces-should-be-illegal

 Exactly!  Encapsulate, insulate, condition--conditioning is going to be a lot cheaper than running and maintaining the dehumidifier, btw.

[Genny Li]

Here is a building science article which explains why MOAR VENTILATION is stupid: https://www.buildingscience.co...

(You don't actually need a flooring in a retrofitted encapsulated crawlspace, because you can just choose not to insulate the ground at all, which is the cheaper solution that is smarter for older houses, as the insulation of the ground returns fairly marginal gains for the huge cost of doing it.  You put a vapor barrier on the ground and crawlspace walls and insulate just the crawlspace walls.  You can think of the ground like an uninsulated slab, which was the standard until like the 90s.)

https://www.buildingscience.co...