Damp Rising - Problem.

[beerthanks]

Seeking advice and best course of action for a problem affecting my shed.

History: Recently brought a new house, here in Dublin Ireland, and the shed was in very poor shape. The roof and joists were all rotten and sagging.
With the help of a lad from Canada we put on a new roof, created a pitch and secured the shed.


Problem: Recently I have started to notice mold, dampening and the first affects of damp rising through the blockwork. I am not sure what to do, or how to ensure that the damp doesn't affect the timberwork holding my roof up.

Open to suggestions, tips or comments. I am seeking a solution to the problem without tearing down the roof.
Thanks for checking in !

 

[Lippyp]

If its rising damp then does the wall have a damp-proof course? This is normally a layer of a thick black plastic or asphalt felt material laid in one of the lowest mortar joints, the idea is this imnpermeable barrier stops any rising damp. If it has (and its usually easy enough to see make sure this hasn't been breached by for example soil being piled against the wall above this level. It'll be below the rendering on the wall. There does look like theres soil piled up against the wall next to the door. If so what would help is to dig this away to below the dpc and see what happens. If you still have a problem (assuming you have gutters and drainage sorted out) then installing a frenmch drain along the walls may help, this is a trench dug alongside thre walls, lined with landscaping fabric and filled with gravel/crushed stone, the fabric then covers the top of the stone and should finish a few inches below ground level and you can then put soil on top to cover it. You can even put some perforated soil drainage pipe in the bottom and run it away to a drain or soakaway away from the building.

 

[bgarrett]

add an earthtube and a chimney. It admits dry air

 

[beerthanks]

Hi Phil, Thanks for your valuable input.

Ive taken a look and have a few answers as follows:

1. I don't think there was any damp-course put in. There was no visible black plastic when I took an inspection.

2. I have made a channel around the wall to prevent moisture buildup against the wall several months ago (see attached). The damp lines inside the wall appear to be showing up in spots along my wall which have not been cleared/which makes sense that the channel is working.

3. Thanks for the idea about creating a French drain - and will investigate this further. It would add a nice touch to the landscaping as well.

Question: Any suggestions going forward on how to treat wood which has been affected by the damp?

(Photos attached for reference - and an Original Photo of the shed before it was renovated)

 

[beerthanks]

add an earthtube and a chimney. It admits dry air

Can you point me in the direction of a good website that explains how the earthtube works, and how to install one? (Thanks in advance)

 

[FluxCore]

RULE: If it's ever gonna be enclosed, then lay thick plastic vapor barrier before concrete is poured....If it's gonna remain an open walled covered slab, then fersure DON'T lay vapor barrier or it will sweat and stay soaking wet.

Your only choice at this point is to attempt to provide plenty of ventilation...not good/cheap/easy when trying to also work at comfortable temps in cold/wet climate.

Ouch!

I'm German/Scottish, but I sure like you Irish guys and especially love your whiskey and red haired women....Yes, I do

 

[Lippyp]

If theres no dpc then you could install a chemical DPC. This involves drilling a mortar course at regular intervals and then injecting a chemical in that then waterproofs that layer. You can hire the kit from most tool hire places and do it yourself. The french drain will help as well. If it was built as a shed then its quite likely they just threw it up with no dpc. In terms of drying out whats there then ventilation is the key, I've just installed a solar powered vent setup over at our holiday home in France using two PC fans, an 80W solar panel and a deep cycle car battery. This is to provide extra ventilation when its shut up when we're not there. If you have mains power then just get a couple of PC fans and a 12V transformer to run the and add some vents. Let the affected timber dry out and then paint it with something like cuprinol to kill any mould/rot spores.

http://www.dampcoursing.com/chemical.html

 

[beerthanks]

RULE: If it's ever gonna be enclosed, then lay thick plastic vapor barrier before concrete is poured....If it's gonna remain an open walled covered slab, then fersure DON'T lay vapor barrier or it will sweat and stay soaking wet.

Your only choice at this point is to attempt to provide plenty of ventilation...not good/cheap/easy when trying to also work at comfortable temps in cold/wet climate.

Ouch!

I'm German/Scottish, but I sure like you Irish guys and especially love your whiskey and red haired women....Yes, I do

With winter on the way and 345 days of rain per year, one thing I can assure you is that I have a pretty good supply of whiskey (mad for the Islay Whiskeys at the moment), wine and my red-head wife

 

[beerthanks]

If theres no dpc then you could install a chemical DPC. This involves drilling a mortar course at regular intervals and then injecting a chemical in that then waterproofs that layer. You can hire the kit from most tool hire places and do it yourself. The french drain will help as well. If it was built as a shed then its quite likely they just threw it up with no dpc. In terms of drying out whats there then ventilation is the key, I've just installed a solar powered vent setup over at our holiday home in France using two PC fans, an 80W solar panel and a deep cycle car battery. This is to provide extra ventilation when its shut up when we're not there. If you have mains power then just get a couple of PC fans and a 12V transformer to run the and add some vents. Let the affected timber dry out and then paint it with something like cuprinol to kill any mould/rot spores.

http://www.dampcoursing.com/chemical.html

Thanks again for the great responses.

I am going to tackle this with my French drain landscaping and working on increasing the ventilation (thanks Phil) for some great tips. Might do a bit of timer treatment work as well.

The more I look around the neighborhood, the more I realize they left out DPC in many of the sheds on my block. Its a real pity, but I am determined to preserve my timber roofing and shed. At the end of the day: once the shed is secure, I'll have more time to continue overhauling the shed.

I have a few other projects on the horizon - building a wine rack for my French wine for the shed. Renovating a workbench and completing my insulation of the shed.

 

[kbs2244]

I don't see any gutters and downspouts.
And with 345 days of rain you shure do need them.
Catch and re-route the water before it get into the ground.

 

[May Pop]

This wont help.

Swamp Castle

 

[beerthanks]

I don't see any gutters and downspouts.
And with 345 days of rain you shure do need them.
Catch and re-route the water before it get into the ground.

You right. But the pitch of the roof drains away from the site behind the shed - into a concrete lane and into drainage. Most of the damp in my yard is fairly standard typical Irish conditions.

Now the soil composition in my backyard is a whole new topic. Its fairly clay type soil, and drains fairly well, but gets 'mushy' when I get a good downpour.
I might post a new thread about this. Its hard to measure, prove and show people how crappy the soil is. I just know it turns to mushy-slush when it rains (almost everyday)! Back to my Whiskey!

 

[beerthanks]

I think this scene was shot in my backyard:

 

[KEH]

I may have posted this before, but during World War II the American GIs who were in Ireland's comment on the weather was "when you can see the hills, it's going to rain, when you can't see the hills it's raining."

I've had similar problems and have to use a sump pump.

KEH