Insulate basement with foamboard, studs?

[PCustoms]

Basement was previously very poorly insulated (1/2 wHite foam). I've since removed paneling, insulation, studs and painted the walls with drylock. Walls below grade appear to be tar coated, unsure of insulation but I don't think there is any. Dehumidifier keeps it below 50% rh (biggest issue here is walkout/drive out door), no standing water.

Plan is to start with a 12x14 room and isnulate the walls.

1St thought is to run foam adhesive vertically, glue 1.5" eps on, and then stud/******** top of the foam. Wood is attached with powder nailer. I assume no additional vapor barrier?

Is there a better way? Could stud (either space off concrete or us PT, $$) and insulate the bays.

 

[mike93lx]

I used 2" foamular and 1x4 strapping all mounted up with spring nails. Then drywalled on top with purple board

This is the process I used : https://www.thisoldhouse.com/how-to/how-to-insulate-basement

Do a plastic sheet moisture test first

 

[yeldogt]

It's all a question of moisture -- if the walls get wet from outside moisture. You will have issues. A dry basement can be framed typically w/o issue.

Many of the foam board system work because the foam acts as a vapor barrier and is inert

 

[foodie]

What is purple board? I am in the same situation as Pcustoms. Do you also use insulation like Roxul or just the foam board? Hope I am not hijacking the thread just adding questions to it to get a better end product for a basement wall.

 

[foodie]

I used 2" foamular and 1x4 strapping all mounted up with spring nails. Then drywalled on top with purple board

This is the process I used : https://www.thisoldhouse.com/how-to/how-to-insulate-basement

Do a plastic sheet moisture test first

I watched that video,...what tape did you use to seal the seams of the foam board?

 

[mike93lx]

I watched that video,...what tape did you use to seal the seams of the foam board?

Just Tyvek tape.

If you really want to ensure a great seal, you could use two layers of 1" board with offset seams, attaching the two layers with foam board adhesive. I think that's overkill, but it is an option.

 

[mike93lx]

What is purple board? I am in the same situation as Pcustoms. Do you also use insulation like Roxul or just the foam board? Hope I am not hijacking the thread just adding questions to it to get a better end product for a basement wall.

sent you a PM back.

Purple is just the MMR (moisture and mold resistant) drywall from National Gypsum.

No rockwool, just the foamular board. I was very tight on space, so framing up a wall and using batts was not really a great option, as I didn't want wood against the concrete. With the foam, strapping and drywall, I'm at a complete assembly of 3.25". That saved at least 2" over a 2x4 wall with an air gap.

 

[foodie]

Thanks so much Mike!

 

[PCustoms]

I used 2" foamular and 1x4 strapping all mounted up with spring nails. Then drywalled on top with purple board

This is the process I used : https://www.thisoldhouse.com/how-to/how-to-insulate-basement

Do a plastic sheet moisture test first

I saw this while back. Never used the spring pins, seems faster to fire some nails in. I do like that the strapping gives room for more foam.

Probably going this route. Hopefullyin a month or so, really need to prioritize some projects with cold weather and holidays coming!

 

[mike93lx]

I saw this while back. Never used the spring pins, seems faster to fire some nails in. I do like that the strapping gives room for more foam.

Probably going this route. Hopefullyin a month or so, really need to prioritize some projects with cold weather and holidays coming!

I don't think you are going to fire a nail through 3/4 of wood plus 2" of foam then into concrete. A ramset just won't do that.

The spring nails work great. I did a 35' wall with a hammer drill. A rotary hammer/sds plus hammer would be massively faster and easier.

 

[bimmer1980]

Take a look at the "InSoFast" foam wall products. It is a stackable, foam product with reinforced strips for screws for the wall board.

Either glue or nail it to the wall and then it is ready for wallboard of your choice.

Saves the expense and hassle of putting on wood furring strips.

It's the product I plan to use when it redo my basement....

 

[b-boy]

I used this site when I did mine 2 years ago. I used 2" XPS, Tyvek tape, and Great Stuff spray foam to seal everything up. I also followed their advice on framing the floor.

https://www.buildingscience.com/documents/bareports/ba-0309-renovating-your-basment/view

For adhesive, I used https://www.amazon.com/dp/B003YHIAHQ/?tag=atomicindus08-20

I tried several others and this one seemed to do the best job.