Contractors often poke hole in the 3mm poly so that the slab dries fast. This was my case. I built my subfloor pretty much the same way you outlined. I did this in my basement and installed real hardwood floor. 10 years and my basement hardwood did not move or buckle at all.
These videos are great. I am going to buy your ebook right now. Love the free info but happy to pay for some good details and pictures. Edit: I wish I had had access to this information when I first started messing with this old dilapidated house.
What changes would you make for an above-ground bathroom build to adjust for the additional moisture and tile? Would a Shluter DITRA uncoupling membrane followed by a KERDI membrane system be sufficient? Would cement board between the Advantech subfloor and the DITRA be necessary for tile or would you skip the Advantech and go directly to a cement board product for the subfloor, followed by DITRA and KERDI? I really appreciate the input!
Check out Nudura Homega polystyrene boards that have wood furring impregnated so you can fasten plywood directly. This is what I used 3.75” homega and then 3/4” plywood glued and screed to wood furring on the insulation boards. Hardwood right on top in my base,ent and zero issues.
Thanks for the good info. I'm curious how you recommend dealing with exterior door thresholds and existing interior walls that won't allow for seamless insulation or vapor barrier. I live in the desert in AZ, so it's fairly dry. However, moisture can still be an issue if not accounted for properly. Cold is less of a problem as well, although it can get frigid in the peak of winter. Undoubtedly, a little floor insulation would be very welcome in those days. As you may have figured out, heat mitigation is our greatest concern. My midcentury cinderblock house is poorly insulated and excessive cooling bills and hotspots are a constant challenge. I'm planning strategies to maximize efficiency and comfort as much as possible. I'm thinking of a couple layers of exterior rigid insulation at least 3-4 inches thick along with elevating the attic insulation to the undercarriage of the roof to allow for incorporating the attic space into the envelope and bringing as many systems inside as possible. The current setup with the ducting going through the unconditioned attic is about as inefficient and counterintuitive as it gets. Another step I've been contemplating is injecting foam into the wall cavities to help boost the R-value. I know it's not ideal, but I think there could be added benefits with moisture and keeping critters and bugs from using the open cavities as a super highway to get around the house. I'd be curious to hear your thoughts on that. Lastly, I am considering adding a shallow underlayment of insulation (possibly DRICORE Insul-Armor) on top of the existing slab-on-grade foundation with LVP directly on top of that. My challenge is to not eat up too much vertical space since the ceiling heights are fixed at a fairly modest 8 ft. and all the exterior doorway lintels are fixed in the block at 80 inches. Since moisture isn't as big of an issue here, I'm wondering if you think the vapor barrier is still advised or necessary. Any step or expense I can avoid would be a benefit, but I don't want to take a chance solely based on expense. Where I'm most stuck in the planning is how the transitions should look at the exterior door thresholds with the 1-inch foam board insulation. It would be nice to extend it under the door to create a thermal break, but that sounds like inviting a host of potential problems. I'm not so much worried about the compressive strength of the foam, but exposure and making it watertight sounds like a challenge. If I don't run it under the door, what do you suggest would be the best method to bring the threshold up to the new floor height with the insulation? I'd love to hear your thoughts. I've watched dozens of your videos, but I haven't seen that detail covered. Please direct me to it if you have. Or I'll just look forward to a response. Thanks again.
There are new OSB flooring tiles that come with a pre-installed rubber tile underneath with grooves to elevate it on top of the slab. Would that work? Would you still need to put insulating foam underneath it?
Great info, thanks for sharing. I appreciate the emphasis on "perfect" air sealing of dimple mat or it will not function properly. How many would haphazardly throw down the mat and not be meticulous about the seams, edges, plumbing penetrations etc.
My below grade subfloor built in 1963 does not have vapor barrier, I’ve been told. Old tiles were removed and black mastic left behind. Not tested. Could I move forward with dimple mat procedure like you’ve instructed in this video?
@@sashajohnson-z4s This is probably your best option if you're dealing with questionable existing conditions in a slab, but it sounds like you're dealing with a crawl space area?
So here with your example, the 2 layers of subfloors are glued and screwed to each other and then floating on top of the insulation ? Not screwing in down to the slab ?
@@ASIRIDesignsI love your videos. Will buy your book on rehabbing an old house. Does that include details on how to seal dimple mat to sump system? Not sure how I would do that…. Thanks for your work
Absolutely! I specify this regularly for basement retrofits. The only difference is that you need a sump pit sealed to the dimple mat so that any water that leaks into that space can be pumped out.
@@ASIRIDesignswouldn't any water that ends up on the slab just drain down through the slab? Sump pit would be for major water intrusion through the foundation
@@fooflateka That would work but I'd switch the vapor barrier to a taped dimple mat instead to prevent potential moisture migration through poorly sealed laps.
ZIP-R isn't designed or warrantied for floor or roof assemblies yet. Plus the compressive strength of their polyiso product is slightly lower than what you would want for this type of application.
*A Guide To Moisture Management For Residential Remodels eBook:* asiri-designs.com/shop/ols/products/moisture-management-for-residential-remodels
i have yet to come across someone who explains it this simply and informs every choice for the design of a slab detail. Very good job!
Great information for a critical issue.
Contractors often poke hole in the 3mm poly so that the slab dries fast. This was my case. I built my subfloor pretty much the same way you outlined. I did this in my basement and installed real hardwood floor. 10 years and my basement hardwood did not move or buckle at all.
These videos are great. I am going to buy your ebook right now. Love the free info but happy to pay for some good details and pictures.
Edit: I wish I had had access to this information when I first started messing with this old dilapidated house.
What changes would you make for an above-ground bathroom build to adjust for the additional moisture and tile? Would a Shluter DITRA uncoupling membrane followed by a KERDI membrane system be sufficient? Would cement board between the Advantech subfloor and the DITRA be necessary for tile or would you skip the Advantech and go directly to a cement board product for the subfloor, followed by DITRA and KERDI? I really appreciate the input!
Check out Nudura Homega polystyrene boards that have wood furring impregnated so you can fasten plywood directly. This is what I used 3.75” homega and then 3/4” plywood glued and screed to wood furring on the insulation boards. Hardwood right on top in my base,ent and zero issues.
Thanks for the good info. I'm curious how you recommend dealing with exterior door thresholds and existing interior walls that won't allow for seamless insulation or vapor barrier. I live in the desert in AZ, so it's fairly dry. However, moisture can still be an issue if not accounted for properly. Cold is less of a problem as well, although it can get frigid in the peak of winter. Undoubtedly, a little floor insulation would be very welcome in those days. As you may have figured out, heat mitigation is our greatest concern. My midcentury cinderblock house is poorly insulated and excessive cooling bills and hotspots are a constant challenge.
I'm planning strategies to maximize efficiency and comfort as much as possible. I'm thinking of a couple layers of exterior rigid insulation at least 3-4 inches thick along with elevating the attic insulation to the undercarriage of the roof to allow for incorporating the attic space into the envelope and bringing as many systems inside as possible. The current setup with the ducting going through the unconditioned attic is about as inefficient and counterintuitive as it gets.
Another step I've been contemplating is injecting foam into the wall cavities to help boost the R-value. I know it's not ideal, but I think there could be added benefits with moisture and keeping critters and bugs from using the open cavities as a super highway to get around the house. I'd be curious to hear your thoughts on that.
Lastly, I am considering adding a shallow underlayment of insulation (possibly DRICORE Insul-Armor) on top of the existing slab-on-grade foundation with LVP directly on top of that. My challenge is to not eat up too much vertical space since the ceiling heights are fixed at a fairly modest 8 ft. and all the exterior doorway lintels are fixed in the block at 80 inches. Since moisture isn't as big of an issue here, I'm wondering if you think the vapor barrier is still advised or necessary. Any step or expense I can avoid would be a benefit, but I don't want to take a chance solely based on expense.
Where I'm most stuck in the planning is how the transitions should look at the exterior door thresholds with the 1-inch foam board insulation. It would be nice to extend it under the door to create a thermal break, but that sounds like inviting a host of potential problems. I'm not so much worried about the compressive strength of the foam, but exposure and making it watertight sounds like a challenge. If I don't run it under the door, what do you suggest would be the best method to bring the threshold up to the new floor height with the insulation? I'd love to hear your thoughts. I've watched dozens of your videos, but I haven't seen that detail covered. Please direct me to it if you have. Or I'll just look forward to a response. Thanks again.
How do you attach the wood subfloor??? 🤔 I'm thinking you can't attach to the concrete because that would compromise the dimple mat, right??
You can glue it to the rigid foam with the special adhesive made for that
There are new OSB flooring tiles that come with a pre-installed rubber tile underneath with grooves to elevate it on top of the slab. Would that work? Would you still need to put insulating foam underneath it?
Great info, thanks for sharing. I appreciate the emphasis on "perfect" air sealing of dimple mat or it will not function properly. How many would haphazardly throw down the mat and not be meticulous about the seams, edges, plumbing penetrations etc.
My below grade subfloor built in 1963 does not have vapor barrier, I’ve been told. Old tiles were removed and black mastic left behind. Not tested. Could I move forward with dimple mat procedure like you’ve instructed in this video?
@@sashajohnson-z4s This is probably your best option if you're dealing with questionable existing conditions in a slab, but it sounds like you're dealing with a crawl space area?
So here with your example, the 2 layers of subfloors are glued and screwed to each other and then floating on top of the insulation ? Not screwing in down to the slab ?
That's exactly right. We also adhere the insulation to the dimple mat. No fastener penetrations through the dimple mat.
@@ASIRIDesigns okay thanks! It works the same on a basement slab too right ?
@@LaJotaFranco Yep! The only difference is that you need a sump pit and ensure it's sealed at that location.
@@ASIRIDesigns Thank you!
@@ASIRIDesignsI love your videos. Will buy your book on rehabbing an old house. Does that include details on how to seal dimple mat to sump system? Not sure how I would do that…. Thanks for your work
loveeee your posts
Thank you so much! More coming every week.
Can’t wait
Love these videos!! A lot of value!
Excellent video. Thank you.
thanks a lot for this video. it shares good information
Could this strategy be used on a basement floor?
Absolutely! I specify this regularly for basement retrofits. The only difference is that you need a sump pit sealed to the dimple mat so that any water that leaks into that space can be pumped out.
@@ASIRIDesigns Interesting, thanks!
If the basement floor has Stegowrap and XPS under it, would you still recommend the dimple mat under plywood or Advantec subflooring?
@@ASIRIDesignswouldn't any water that ends up on the slab just drain down through the slab? Sump pit would be for major water intrusion through the foundation
well done ,thank you
Thank you.
How about 15mil on slab, then roth panels, some thinset on top and then tile?
@@fooflateka That would work but I'd switch the vapor barrier to a taped dimple mat instead to prevent potential moisture migration through poorly sealed laps.
@@ASIRIDesigns what’s to be done with raised footing?
@@ASIRIDesigns by the way, what if there is no vapor barrier under the slab on grade?
So what if the sill plate area has moisture issues? Does your ebook address this?
Wouldn't a ZIP R6,9,12 panel and one layer of Advantech work just as well, as what you have shown above?
ZIP-R isn't designed or warrantied for floor or roof assemblies yet. Plus the compressive strength of their polyiso product is slightly lower than what you would want for this type of application.
SOLD $18 worth every penny
So all the moisture will go in to the wall. No.