Gluing (?) wood to concrete
 

I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?
--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

I've never managed to get concret and wood to glue successfully, so I'd say
sealant and screws as per your idea is best.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Peter Percival" wrote in message
...
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It has a
made-up as it was constructed look about it.) The wood is rotten and I
need to replace it. How can I attach the new wood to the concrete? I
could use screws--those things that expand against the hole they are in
when an internal screw is tightened--but that will leave a crack 'twixt
concrete and wood where the rain might get in. So I need (I think) an
adhesive cum sealant. Any suggestions?
--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

Brian Gaff wrote:
I've never managed to get concret and wood to glue successfully, so I'd say
sealant and screws as per your idea is best.

Thank you. What sealant would you recommend?

I wrote:
I have inherited a shed made of cast (or moulded, whatever the word
is) concrete for the lower walls on which the rest is built of wood.
(It has a made-up as it was constructed look about it.) The wood is
rotten and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the
hole they are in when an internal screw is tightened--but that will
leave a crack 'twixt concrete and wood where the rain might get in.
So I need (I think) an adhesive cum sealant. Any suggestions?

--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

On 23/05/2013 11:49, Peter Percival wrote:
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?

Not quite enough description. Do you mean the base is made of those
pre-cast panels which sometimes whole garages are made of? These are
thicker at the edges where there is reinforcing rod, and thinner in the
middle.

Or are you saying that the walls were cast in place with formwork which
was subsequently removed. How thick are they?

And how is the wood fixed? Does it overhang the concrete, or is it
mounted on it.

You *don*t generally want an expanding thingy in the concrete, that is
asking for cracks unless the thickness is substantial. But if you rest
something like a wall plate on top of the concrete, then hang panelling
/ T&G / Feather Edge outside, you could prevent it blowing off in the
wind by having the panel overhanging the concrete, and bolted to it with
normal coach bolts going through holes in the panel below the rebar. For
adhesive / sealant, any sort of external mastic / frame sealant should
do. But I would want some sort of mechanical fixing as well against wind
forces.

Gluing (?) wood to concrete
 

On 23/05/2013 11:49, Peter Percival wrote:
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?


you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Gluing (?) wood to concrete
 

On 23/05/2013 11:49, Peter Percival wrote:
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?

I would be wary of using expanding fixing on thin section concrete -
there is a risk of just splitting or spalling it. You could drill the
concrete and insert threaded rods into resin, then use those for
mechanical fixing. Finally finish with a silicone sealant to make the
join waterproof while allowing for natural movement of the wood.

--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Gluing (?) wood to concrete
 

newshound wrote:
On 23/05/2013 11:49, Peter Percival wrote:
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?

Not quite enough description. Do you mean the base is made of those
pre-cast panels which sometimes whole garages are made of? These are
thicker at the edges where there is reinforcing rod, and thinner in the
middle.

Or are you saying that the walls were cast in place with formwork which
was subsequently removed.

Yes, I think so.

How thick are they?

Five inches.

And how is the wood fixed? Does it overhang the concrete, or is it
mounted on it.

Mounted on it, and so rotten (some of it just dust) that I cannot tell
how it was attached.

You *don*t generally want an expanding thingy in the concrete, that is
asking for cracks unless the thickness is substantial. But if you rest
something like a wall plate on top of the concrete, then hang panelling

Wall plate?

/ T&G / Feather Edge outside, you could prevent it blowing off in the
wind by having the panel overhanging the concrete, and bolted to it with
normal coach bolts going through holes in the panel below the rebar. For
adhesive / sealant, any sort of external mastic / frame sealant should
do. But I would want some sort of mechanical fixing as well against wind
forces.

--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

Rick Hughes wrote:
On 23/05/2013 11:49, Peter Percival wrote:
I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?


you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Excuse my ignorance, but I've never heard of resin fixings.

--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

Peter Percival wrote:
Rick Hughes wrote:
[snip]

you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Excuse my ignorance, but I've never heard of resin fixings.

You drill a hole, inject a liquid resin and hardener then insert a threaded
rod and wait for the resin to harden before using the rod to bolt down the
attachment.

Another method is to use non-expanding masonry screws. These need an exact
hole drilling so you need an SDS drill and the appropriate bit.

http://www.toolstation.com/shop/Scre.../sd1950/p82307

Also available as "Multi-Monti" from Screwfix and other places.

--
€¢DarWin|
_/ _/

Gluing (?) wood to concrete
 

Steve Firth wrote:
Peter Percival wrote:
Rick Hughes wrote:
[snip]

you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Excuse my ignorance, but I've never heard of resin fixings.

You drill a hole, inject a liquid resin and hardener then insert a threaded
rod and wait for the resin to harden before using the rod to bolt down the
attachment.

That sounds like a good idea. Let's suppose I fix the wood to the
concrete thus, there will be a gap. It there something like the stuff
one puts round the edge of baths (silicone something-or-other) that I
can fill that gap with, but suitable for out-door use?

Another method is to use non-expanding masonry screws. These need an exact
hole drilling so you need an SDS drill and the appropriate bit.

Otoh "exact" is a bit worrying.

http://www.toolstation.com/shop/Scre.../sd1950/p82307

Also available as "Multi-Monti" from Screwfix and other places.

--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Gluing (?) wood to concrete
 

Peter Percival wrote:
Steve Firth wrote:
Peter Percival wrote:
Rick Hughes wrote:
[snip]

you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Excuse my ignorance, but I've never heard of resin fixings.

You drill a hole, inject a liquid resin and hardener then insert a threaded
rod and wait for the resin to harden before using the rod to bolt down the
attachment.

That sounds like a good idea. Let's suppose I fix the wood to the
concrete thus, there will be a gap. It there something like the stuff
one puts round the edge of baths (silicone something-or-other) that I can
fill that gap with, but suitable for out-door use?

When we built our barn/garage it was done by building an oak frame on dwarf
walls. The wall plate was screwed to the wall using Monti screws. The only
material between the wall plate and the wall is plastic DPC. The lowest
weatherboard covers the gap between wall plate and wall. A better solution
than sealant IMO.

If you must use sealant I suggest either polysulphide or MS Polymer. I've
used both and they do a good job of stopping moisture penetrating wood if
you get an even coat on the wood surface that will mate against the wall.

Another method is to use non-expanding masonry screws. These need an exact
hole drilling so you need an SDS drill and the appropriate bit.

Otoh "exact" is a bit worrying.

More exact than you will get with an ordinary hammer drill. An SDS is
ideal, use screws long enough to ensure that there's 40mm or so of screw in
the concrete.

--
€¢DarWin|
_/ _/

Gluing (?) wood to concrete
 

On May 24, 1:55*pm, Steve Firth wrote:
Peter Percival wrote:
Rick Hughes wrote:

[snip]

you could use resin fixings, no risk of cracking concrete and hole is
fully filled

Excuse my ignorance, but I've never heard of resin fixings.

You drill a hole, inject a liquid resin and hardener then insert a threaded
rod and wait for the resin to harden before using the rod to bolt down the
attachment.

Another method is to use non-expanding masonry screws. These need an exact
hole drilling so you need an SDS drill and the appropriate bit.

SDS for 6mm holes? nah ordinary hammer drill will suffice

Jim K

Gluing (?) wood to concrete
 

"Peter Percival" wrote in message ...

I have inherited a shed made of cast (or moulded, whatever the word is)
concrete for the lower walls on which the rest is built of wood. (It
has a made-up as it was constructed look about it.) The wood is rotten
and I need to replace it. How can I attach the new wood to the
concrete? I could use screws--those things that expand against the hole
they are in when an internal screw is tightened--but that will leave a
crack 'twixt concrete and wood where the rain might get in. So I need
(I think) an adhesive cum sealant. Any suggestions?




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