Stopping Condensation on the Bottom of a Lead Gutter

[RobFJ]

I've just bought a house and it has a conservatory where one side is the original cob/flint/line mortar garden wall.

Along that side of the conservatory is a rectangular lead gutter, about 10" wide (flat base) and 3-4 metres long. It is internal to the conservatory.

In cold weather, the differential air temperature between inside and outside the conservatory is such that water condenses onto the lead at such a rate that it drips down the wall causing large patches of damp that will last throughout the colder months. As such, it is a great breeding ground for green slimey algae

Previously, the gutter had a plywood soffit fitted underneath but that was a disaster as it just became saturated, mouldy and rotten. Things took even longer to dry out than having the lead exposed.

Has anyone got any ideas on how I can stop the build-up of water in the colder months hence keep the wall dry. (One thing in my favour is I have pretty good access to the gutter.)

Thanks

Rob

 

[footprints]

If you are certain its condensation not a leak, I would replace the soffit with insulation packed in behind it.

 

[RobFJ]

If you are certain its condensation not a leak, I would replace the soffit with insulation packed in behind it.

Tx for the quick reply. My first thought was a leak also but, over a year, I've seen the gutter completely dry in summer months during very heavy rain and totally soaking in winter when there's been no rain for days.

 

[ree]

There are a couple of issues with your description of this lead gutter arrangement - perhaps you could post pics?

 

[^woody^]

green slimey algae

.... Is not something you tend to get from condensation moisture

 

[RobFJ]

There are a couple of issues with your description of this lead gutter arrangement - perhaps you could post pics?

/Ree/,

Pic has been uploaded. For info, the leadwork is totally horizontal side to side and, as you'd expect, has a gentle slope along its length

View media item 94327
/Woody/

Agree it could also be condensation but water actually drips off the bottom of the gutter onto the wall where the algae is (you can see the marks in the top corner of the wall) - 80% of the wall is also dry. So I need to stop that dripping first and then see if there is still a problem

 

[ree]

Thanks for the pic.

Sheet lead lengths should be no more than 1500mm or 5ft in length, if your gutter is a single 3m length then its almost a certainty that it has hairline splits.

During a warm dry day, clean off the upper and the lower surfaces of the lead - totally dry and clean. Same with the affected wall. Then, from the discharge end begin to gently water test the gutter. Pour some water over 300mm-500mm sections at a time, and wait and watch below.

I presume that the black length of whatever, is a gutter supporting batten? Maybe a pic from above the gutter might help?

 

[RobFJ]

Thanks for the pic.

Sheet lead lengths should be no more than 1500mm or 5ft in length, if your gutter is a single 3m length then its almost a certainty that it has hairline splits.

I presume that the black length of whatever, is a gutter supporting batten? Maybe a pic from above the gutter might help?

Tx for the reply.

To keep my first question fairly simple I omitted a couple of things. The gutter has been inspected both sides for hairline cracks and has been water-tested (no leaks or cracks found) and watched during massive downpours (eg today we had 10mm of rain in an hour and the underside is totally dry).

The black timber attached to the wall is the where the supporting timbers for the gutter floor and soffit screwed in.

The gutter isn't a single length - it has a deliberate step down part way of a couple of inches