Floor joists set into concrete

[jfunderburk (Joe Funderburk, CMI)]

@gmathias1

The Alberta building code does allow untreated wood to be in contact with concrete as long as the floor joists are at least 8"(200mm) agove grade. I am not a fan and would not do it in my home but it is done every day here. Once you start into home inspection you will see it all the time.
We do not use the IRC even though alot of the code requirements are the same. We use the Alberta building code or the NBC. NBC is bare minimum code requirements. The ABC is better as alot of the codes are different and factor in our weather, moisture…
Hope this helps

Does the Alberta building code allow joists to be EMBEDDED in concrete that is in direct contact with the ground? The IRC distinguishes between contact < 8" and contact by being embedded.

[jjonas (Jeffrey Jonas)]

@jjones12

Jeffrey what did i miss?..was it a good flip out from a jerk? I think its so funny how one guy says one thing and another say he or she is wrong. I personally verify my facts with my teacher and mentor and books but am STILL told I am wrong … There really should be a national SOP and everybody should follow it the same way - it would squish some of these flip outs - but… I still am upset I missed it, what was the link?

Take your pick, there are many, and has been going on for a while. :neutral:

[gmathias1 (Greg Mathias, CCHI, CMI)]

@jfunderburk

Does the Alberta building code allow joists to be EMBEDDED in concrete that is in direct contact with the ground? The IRC distinguishes between contact < 8" and contact by being embedded.

No, as I said, just be 8" above grade

[kwood (KEVIN WOOD, CMI)]

Just for the sake of interest it is 6 inches in OBC 2006.
(3) Structural wood elements shall be pressure-treated with a preservative to resist decay,
(a) where the vertical clearance between structural wood elements and the finished
ground level is less than 150 mm, or
(b) where,
(i) the wood elements are not protected from exposure to precipitation, and
(ii) the configuration is conducive to moisture accumulation.

[belliott (Bob Elliott, 450.0002662)]

The problem is different areas have different weather and different codes.
Nobody here thinks porous concrete in direct contact with wood is a good thing I am sure.

Just take a look at Will Deckers sight showing rotted wood joists embedded in split block as an example.

[clawrenson (Claude Lawrenson)]

Right from the provincial code…

[ryoung7 (ROBERT YOUNG, CMI)]

@jfunderburk

Jeffery, you’ll see that untreated wood can be in contact with concrete. See Item 2.

2009 IRC SECTION R317
PROTECTION OF WOOD AND WOOD
BASED PRODUCTS AGAINST DECAY

R317.1 Location required. Protection of wood and wood
based products from decay shall be provided in the following
locations by the use of naturally durable wood or wood that is
preservative-treated in accordance with AWPA U1 for the species,
product, preservative and end use. Preservatives shall be
listed in Section 4 of AWPA U1.1. Wood joists or the bottom of a wood structural floor
when closer than 18 inches (457 mm) or wood girders
when closer than 12 inches (305 mm) to the exposed
ground in crawl spaces or unexcavated area located
within the periphery of the building foundation.

2. All wood framing members that rest on concrete or
masonry exterior foundation walls and are less than 8
inches (203 mm) from the exposed ground.

3. Sills and sleepers on a concrete or masonry slab that is in
   direct contact with the ground unless separated from
   such slab by an impervious moisture barrier.

4. The ends of wood girders entering exterior masonry or
   concrete walls having clearances of less than 1/2 inch
   (12.7 mm) on tops, sides and ends.

5. Wood siding, sheathing and wall framing on the exterior
   of a building having a clearance of less than 6 inches (152
   mm) from the ground or less than 2 inches (51 mm) measured
   vertically from concrete steps, porch slabs, patio
   slabs, and similar horizontal surfaces exposed to the
   weather.

6. Wood structural members supporting moisture-permeable
   floors or roofs that are exposed to the weather, such
   as concrete or masonry slabs, unless separated from such
   floors or roofs by an impervious moisture barrier.

7. Wood furring strips or other wood framing members
   attached directly to the interior of exterior masonry walls
   or concrete walls below grade except where an approved
   vapor retarder is applied between the wall and the furring
   strips or framing members.

Code Commentary:
This section addresses the need for minimum protection
against decay damage for wood members located
in certain locations.

For those portions of a wood-framed structure that
are subject to damage by decay, the code mandates
that the lumber be pressure-preservative treated or be
naturally durable wood, or be of a species of wood
having a natural resistance to decay. Naturally durable
wood by definition is the heartwood of decay-resistant
redwood, cedars, black locust and black walnut.

Item 1: Crawl spaces and unexcavated areas under
a building usually contain moisture-laden air. These
spaces must be ventilated in accordance with Section
R408 to remove as much moisture as possible before
it causes decay. Wood placed a minimum specified
distance above grade in unexcavated under-floor areas
or crawl spaces, as shown in Commentary Figure
R317.1(1), need not be either preservative-treated
wood or wood that is naturally decay-resistant durable
wood. These clearances below floor joists and beams
are deemed to be the minimum necessary to allow adequate
circulation and removal of moisture from the air
and from the wood framing members. Such clearances
apply within the exterior wall line of the building
foundation.

Item 2: Foundation walls will absorb moisture from
the ground and by capillary action move it to framing
members that are in contact with the foundation. Unless
a minimum clearance of 8 inches (203 mm) is
maintained from the finished grade to wood sills resting
on concrete or masonry exterior foundation walls,
decay-resistant or preservative-treated wood, as
shown in Commentary Figure R317.1(2), must be
used. The 8-inch (203 mm) clearance specified in this
section has been determined to be large enough to
prevent wetting of wood framing members under most
circumstances.

Item 3: Concrete and masonry slabs that are in direct
contact with the earth are very susceptible to
moisture because of absorption of ground water. This
can occur on interior slabs, as well as at the perimeter.
In the case of wood sills or sleepers placed on concrete
or masonry slabs, decay-resistant wood or pressure-
treated wood is required where the slabs are in
direct contact with the ground, as illustrated in Commentary
Figure R317.1(3). Concrete that is fully separated
from the ground by a vapor barrier is not in direct
contact with earth.

Item 4: A minimum 1/2-inch (12.7 mm) clearance
along the top, sides and ends of wood members projecting
into exterior masonry or concrete walls must be
maintained, as illustrated in Commentary Figure
R317.1(4), unless the wood is treated or is of a species
that is naturally decay resistant.

Item 5: Experience has shown that wood siding may
extend below the sill plate to within 6 inches (152 mm)
of the earth without decaying. Commentary Figure
R317.1(5) shows the required minimum 6-inch (152
mm) clearance from the ground for wood siding,
sheathing and wall framing on the exterior of a building.
It should not be in direct contact with the foundation
wall. If the sheathing is located over a concrete
step or slab, the clearance may be reduced to 2 inches
(51 mm) minimum.

Item 6: Concrete or masonry slabs that serve as
roofs or floor systems that are exposed to the weather
are very susceptible to moisture from rain or snow. If
these slabs are supported by wood, the wood must be
decay resistant or must be separated from the slabs by
vapor barriers so there is not direct contact. This is
similar to Item 3.

Item 7: When a basement area is finished, a com-
mon practice is to provide wood furring strips on top of
the concrete or masonry walls for attachment of finishes.
These furring strips must either be of decay-resistant
material or must be separated from the wall by
a vapor barrier. This will prevent the moisture from
moving through the walls and rotting the furring strips,
and even possibly transferring the moisture to the inside
finish materials.

Splitting hairs Joe.
Wood Resting on concrete. Like sill plates or ledger boards for decks.

Those are in the concrete.
Jeffrey is right.
Need to be treated or an opening of 1/2"
The lumber should be pressure treated and or separated by a Barrier.IE: Wrapped in Blue skin, Real Dry or .Waterproof Membrane. OR an air gap of 1/2 or 5/8 " I could be wrong on the gap or opening.Then its good to go.

Then there are the fasteners for treated wood [treated wood](ASTM B-695, Class 55, minimum.)so the do not degrade.ASTM B-695, Class 55, minimum.
Most is in the link.

[ryoung7 (ROBERT YOUNG, CMI)]

[quote=“clawrenson, post:26, topic:71884”]

Alberta Building Code - reg 9.3.2.9 Termite and Decay Protection

2. Structural wood elements shall be pressure treated with a preservative to resist decay where
   a) the structural wood elements are in contact with the ground, or
   b) the vertical clearance between structural wood elements and the ground is less than 150 mm - see also 9.23.2.2 and 9.23.2.3

Generally Alberta is considered free of termites* and rats HA HA HA

9.23.2.2 Protection from Decay (notes)

1. Ends of wood joists, beams and other members framing into masonry or concrete shall be treated to prevent decay where the bottom of the member is at or below ground level, or a 12 mm air space shall be provided at the end and sides of the member.

Best practices - wood exposed to moisture for long periods - will eventually decay.

9.23.2.3 Protection from Dampness

1. Except as permitted in sentence 2, wood framing members that are not pressure treated with a wood preservative and which are supported on concrete in contact with the ground or fill shall be separated from the concrete by not less than 0.05 mm polyethylene film, or Typs S roll roofing.
2. Dampproofing material referred to in sentence 1 is not required where the wood member is at least 150 mkm above the ground. (approximately 6 inches)/QUOTE
   Jus a bit of jocularity.

[clawrenson (Claude Lawrenson)]

That’s right - ignore - my post…because yours make much more sense!

[ryoung7 (ROBERT YOUNG, CMI)]

@clawrenson

That’s right - ignore - my post…because yours make much more sense!

?
You makes sense.

[kwood (KEVIN WOOD, CMI)]

Claude in view of the amount of posts you make it is probably a good idea for you to check your grammar.
…because yours make much more sense!

[ryoung7 (ROBERT YOUNG, CMI)]

Hope this helps.
Just reading it now.Protection Against decay R3 19.1 LOCATION REQUIRED

2006 IRC.
PROTECTION AGAINST DECAY R3 19.1](http://www.conradlumberco.com/pdfs/TreatedWood2006IRC.pdf)Location Required.
Protection from decay shall be provided in the following locations by the use of naturally durable wood or
wood that is preservative-treated i n accordance with American Wood-Preservers’ Association (AWPA) U1 for
the species, product, preservative and end use. Preservatives shall be listed i n Section 4 of AWPA U1.

ICC

2304.11.4.1 Posts or columns. Posts and columns supporting permanent structures that are embedded in concrete that is in direct contact with the earth, embedded in concrete that is exposed to the weather or in direct contact with the earth shall be of preservative-treated wood.

2304.11.4.2 Wood structural members. Wood structural members that support moisture-permeable floors or roofs that are exposed to the weather, such as concrete or masonry slabs, shall be of naturally durable or preservative-treated wood unless separated from such floors or roofs by an impervious moisture barrier.

[kwood (KEVIN WOOD, CMI)]

Robert Alberta has there own Building Code so this cannot be used.
Greg’s is the correct one to use.
I also tell my clients that it is OK to have it 6 inches from grade as a minimum but is it smart to do so.

[jallingham (John Allingham)]

Code in Alberta is probably the same as Ontario

9.23.2.2. Protection from Decay
(1) Ends of wood joists, beams and other members framing into masonry or concrete shall be treated to prevent decay
where the bottom of the member is at or below ground level, or a 12 mm air space shall be provided at the end and sides of
the member.

[rjude (Robert Jude, HI00900033)]

the wood will rot away, treated or not. concrete contains moisture. local codes may allow it but that doesnt make it a good idea.

[kshepard (Kenton Shepard, CMI)]

@jiverson

Hi,

My sister is having a house built in Calgary, Alberta. She wanted me to go by to see if anything was wrong. Since I am new to home inspecting (no license yet, process of getting peer review done) I had a question about the picture with floor joists set into concrete that is not PT or no barrier between the two. I was told wood and concrete should not make contact unless PT or barrier in between. Does anyone know in Alberta if this is right?

Jerrod, it’s not OK.
Wood beams can rest in beam pockets formed into concrete foundation walls, but they need to have an air space around them so that if they get wet they can dry. Floor joists, pressure treated or not, should not be cast into a wall like that. Even with beams in pockets, the pockets don’t extend through the wall.

The proper way to build that would have been to:

1. Bolt a ledger to the inside of the foundation wall and rest the joists in hangers nailed to the ledger so that the wall height doesn’t matter… or

2. Build the foundation wall low enough so that the joists rest on a plate bolted to the top of the foundation so that the top of the bolted plate is bottom of joists, … 0r

3. Use top-flange hangers that nail to a plate anchor-bolted to the top of the wall, so that the top of the top of the bolted plate is top of joist.

There are long-established methods for constructing a framed floor that butts the inside of a concrete foundation wall and what’s shown in that photo is not one of them. It’s simply bad practice.

Look in any framing book or Architectural Graphic Standards for proper methods.

There have been millions of homes built with wall bottom plates of pressure-treated hemlock (hem-fir) that are anchor-bolted to a concrete slab, so pressure-treated contact with concrete is OK, as long as there’s drying space.

[jiverson (Jerrod Iverson)]

Thanks for the great feed back. Ken, I like the discription you provided it was explained really well.

Thanks again everyone.

[ryoung7 (ROBERT YOUNG, CMI)]

@kshepard

Jerrod, it’s not OK.
Wood beams can rest in beam pockets formed into concrete foundation walls, but they need to have an air space around them so that if they get wet they can dry. Floor joists, pressure treated or not, should not be cast into a wall like that. Even with beams in pockets, the pockets don’t extend through the wall.

The proper way to build that would have been to:

1. Bolt a ledger to the inside of the foundation wall and rest the joists in hangers nailed to the ledger so that the wall height doesn’t matter… or

2. Build the foundation wall low enough so that the joists rest on a plate bolted to the top of the foundation so that the top of the bolted plate is bottom of joists, … 0r

3. Use top-flange hangers that nail to a plate anchor-bolted to the top of the wall, so that the top of the top of the bolted plate is top of joist.

There are long-established methods for constructing a framed floor that butts the inside of a concrete foundation wall and what’s shown in that photo is not one of them. It’s simply bad practice.

Look in any framing book or Architectural Graphic Standards for proper methods.

There have been millions of homes built with wall bottom plates of pressure-treated hemlock (hem-fir) that are anchor-bolted to a concrete slab, so pressure-treated contact with concrete is OK, as long as there’s drying space.

:)
I concure with kenton. An airspace is needed. Direct contact is not proper building practices.
The project will see as time evolves.

[An_HI]

@jiverson

Hi,

My sister is having a house built in Calgary, Alberta. She wanted me to go by to see if anything was wrong. Since I am new to home inspecting (no license yet, process of getting peer review done) I had a question about the picture with floor joists set into concrete that is not PT or no barrier between the two. I was told wood and concrete should not make contact unless PT or barrier in between. Does anyone know in Alberta if this is right?

From the pictures, it appears that these are not floor joists extended through the foundation but is inset 1"x4" strapping to which a downward extension of the OSB sheathing will eventually be installed and then the weather resistive barrier and siding. The wood appears to be at least 15- 18" above the finished grade so soil moisture will not be a problem.

To all others, wood in contact with concrete is not a problem in and of itself. It **could **be a rot problem when untreated wood in the concrete or in contact with the concrete is within 6"(Canadian NBC) / 8" (CMHC) of a moisture source such as the soil.

[ryoung7 (ROBERT YOUNG, CMI)]

It is obviously not floor joists HI.
It is not treated, or I should say it does not appear to be treated wood from where I sit.
I see 2" x…material. It is vertical installed to accept some form of sheathing or skirting. If it is not mechanically fastened and flashed properly I see issues before long.
So why do deck ledger have to be flashed, countered and lagged bolted into the wall. Live load right ?

1" by x … or 3/4 actually when dressed would be cupped by now.
2" by x… is 1.75 x…