Is this rot and what can I do about it?

[trojanhawrs]

Built myself a timber framed garage and it's been sitting insulated for the last 6 months or so, but not heated and no inside wall covering. Some of the insulation might have been a touch damp. Have got a few spots along the bottom plate that look like moisture/rot has got to them, anyone seen stuff like this before?
Know I should have put plastic between the wood and concrete but it's strange that it's so localised.
Outside picture is where that is, pretty sure theres not water getting in there.

 

[Bonni]

Rule number one, never insulate something/a room that you don't heat.

 

[trojanhawrs]

Is that a rule?

 

[foxhole]

Doesn’t seem to be anything at base to cast off rain .?

 

[opps]

I cannot see where the water ingress is from.

Years ago, when I built my garage I was gifted a 4 inch tall timber door step. It was so deep, and set so far down that water used to seep under it.

I drilled a series of holes in to the doorstep and squirted in expanding foam (under pressure). The foam snuck in under the doorstep and has successfully prevented any water ingress over the last 20 years.

You might be able to do something in your set up. Drill holes 2" apart and close to where the flooring plate meets the exterior. Make sure that the hole is the same diameter as the plastic hose on the foam can. Squirt until you notice slight push back, then move on to the next hole.

After drilling- pour a small amount of water in. I will help with both adhesion and curing times.

Use a multi-use drill bit- eg https://www.screwfix.com/p/bosch-ex...terial-drill-bit-set-4-piece-set/138KY?tc=HB4

That way if you hit the concrete, you won't damage the drill bit.

 

[big-all]

to me it looks like something spilt like stain
if it was coming from outside and underneath, you would not have the damp not full width at the wall yet full width on the inside edge farthest away from the damp source
also random spots and jagged edges not normal with damp spread

 

[trojanhawrs]

Doesn’t seem to be anything at base to cast off rain .?

There isn't no, rain shouldnt be able to get under the cladding as its level with the slab but I suppose it could be bouncing off the ground and in? I have a concrete path on one side and the bottom board has weathered a lot more than the other sides due to the rebounding rain.
What would you suggest?

 

[trojanhawrs]

I cannot see where the water ingress is from.

Years ago, when I built my garage I was gifted a 4 inch tall timber door step. It was so deep, and set so far down that water used to seep under it.

I drilled a series of holes in to the doorstep and squirted in expanding foam (under pressure). The foam snuck in under the doorstep and has successfully prevented any water ingress over the last 20 years.

You might be able to do something in your set up. Drill holes 2" apart and close to where the flooring plate meets the exterior. Make sure that the hole is the same diameter as the plastic hose on the foam can. Squirt until you notice slight push back, then move on to the next hole.

After drilling- pour a small amount of water in. I will help with both adhesion and curing times.

Use a multi-use drill bit- eg https://www.screwfix.com/p/bosch-ex...terial-drill-bit-set-4-piece-set/138KY?tc=HB4

That way if you hit the concrete, you won't damage the drill bit.

Cheers, I'm still not sure it's water getting in or what exactly.

 

[trojanhawrs]

to me it looks like something spilt like stain
if it was coming from outside and underneath, you would not have the damp not full width at the wall yet full width on the inside edge farthest away from the damp source
also random spots and jagged edges not normal with damp spread

It does look like that yeah but I definitely haven't had any stain near it. I thought it could have been a reaction to the expanding foam or not being able to breathe because of it, it's in 3 distinct places though and one bit did look like it had spores on it. Other bits that have been foamed are fine

 

[big-all]

any staining on the back off the osb that was covering it??

 

[trojanhawrs]

Housewrap, 25mm battens and the cladding you see in pic 1.
Edit - must have misread that but I can't easily see the back of the OSB and not keen to pull cladding off if I can avoid it

 

[JohnD]

Show us the outside

Especially the eaves, gutters and downpipes that keep rain away from the walls

Does the cladding overhang the base, preventing rain from falling on it and pooling?

 

[trojanhawrs]

Will get some better pictures but these 2 side photos were taken last year, back one is recent. Still haven't fitted guttering on the other side, seemed less important as it's just soil and weeds rather than concrete. Think my overhangs are around 150-200mm. I've since straightened the front gutter section it was a bit high initially. You can see my downpipe shoe on the bottom left of the back photo.
The OSB overhangs the slab by about an inch and the cladding is on a level with it, or there abouts.

 

[JohnD]

Is the wet patch on the unguttered side?

Is the wet patch near a window or other opening?

It does look to me like water has been running in.

Unless you spilt a can of something?

 

[trojanhawrs]

There's actually a wet patch on each wall. One about a metre in on the left wall, the one pictured at the back 600 or so in from the left and half way down on the side door wall