Summerhouse rotting in corner

[stringman]

We have bought a house with a lovely little summerhouse.
The problem is the shiplap rotting on one corner (so 2 sides of the wall) this damage extends at its worse about 40 cm on some bits of cladding. The previous owners just patched it up for the inside and painted the outside.

I know what ever I do will only postpone the inevitable but if I could do a repair that lasts a year or so it would be great.

some thoughts I have had are
filling the gaps between the rotten wood and the upright with expanding foam and then cover that with some vertical strips of either treated wood or pvc cladding then painting ( this is more to prevent more water/ivy damage.

cutting back the damaged cladding to the next upright beam and inserting a new piec.
obviously this will be better but will be quite a large job.

Any thoughts?

Thanks in advance

 

[big-all]

pictures off the area
do you have gutters
it the cladding clear off the ground by at least 25mm preferably more
is all wood isolated from the ground/base sufficient to stop water transfer

 

[stringman]

I don't have pictures of the areas as I am away at the moment.
I don't theink there are gutters but there is an overhang.
I'm not sure about the other questions.

any thoughts on the temporary repair though?

 

[Chud]

I'm no expert but unless you thoroughly treat the rot I would think your temporary repair would only make things worse. It will also make a proper repair far more difficult.

I would be inclined to bite the bullet and replace the affected cladding and at the same time treat the timber frame under the cladding with a preserver/rot killer.

 

[Chud]

As others have said a picture would give a better idea though!

 

[r896neo]

You will find it almost impossible to patch repair because the waterproofing of the building is formed by the overlapping tongues and grooves of the cladding Without a tongue locked into the groove above water will just trickle in the joint between the boards. This makes removing one board and replacing it impossible. You need to remove all boards down to ground level or up to roof level (whichever is closer) and work back to maintain the integrity of the tongues. Unfortunaetly with basic 12mm cladding fixed with gun fired ringshank nails it is very hard to remove it without breaking it or damaging it. So you will need a few new boards.

If none of this makes sense it will become abundantly and frustratingly clear as soon as you start.

 

[big-all]

You will find it almost impossible to patch repair because the waterproofing of the building is formed by the overlapping tongues and grooves of the cladding Without a tongue locked into the groove above water will just trickle in the joint between the boards. This makes removing one board and replacing it impossible. You need to remove all boards down to ground level or up to roof level (whichever is closer) and work back to maintain the integrity of the tongues. Unfortunaetly with basic 12mm cladding fixed with gun fired ringshank nails it is very hard to remove it without breaking it or damaging it. So you will need a few new boards.

If none of this makes sense it will become abundantly and frustratingly clear as soon as you start.

thats why i screwed my shiplap on
i have incidentally just replaced 3 planks after 11 years not for rot but because the cowboy ex neighbour who i paid to paint with ducks back had skimped on paint where it couldnt be seen causing the planks to disconnect and cup over the next few years
i had subsiquentaly painted them twice properly after about 4 years and again twice at 7years but the cupping had set in and was unrecoverable
so i unscrewed 4 planks from the middle up just enough to bow out and unclip the tounge without damage to the groove
i replaced the damaged planked with the top plank i removed the back off the groove with a router the screwed into position
i gave the new planks 3 coats after instalation then a further 2 to match the protection lever off the origional planks

this is my shed 11 years ago before any finishing
http://s21.photobucket.com/user/bigall2005/media/e1e47346.pbw.html?sort=3&o=15

 

[LeadFarmer]

I have the same problem, I've cut down an overgrown bamboo plant to discover it has rubbed against the summerhouse and worn it away.

Seeing as the damage is in the lower half of the shed, I assume I need to remove the boards from the bottom up and replace?

Also, where would I get boards to match and what are they called? Heres a profile view of the end of the boards...

 

[ntb]

The boards are shiplap. Available at most timber and fencing places.

 

[LeadFarmer]

The boards are shiplap. Available at most timber and fencing places.

Thanks, Ill go get some.

 

[JohnD]

the lower ones in particular should be generously treated on all surfaces, including the back, with a spirit based wood preserver, after cutting and drilling but before fixing. It is much easier to do a thorough job before, rather than after they have been fixed. Also with your water-repellent stain.

When I did mine, I cut a few extra boards to length, treated them, and tucked them between the studs behind the cladding for spares.

 

[LeadFarmer]

the lower ones in particular should be generously treated on all surfaces, including the back, with a spirit based wood preserver, after cutting and drilling but before fixing. It is much easier to do a thorough job before, rather than after they have been fixed. Also with your water-repellent stain.

Sounds good. Would my Cuprinol Heritage Shades Old English Green go on over the top of a spirit based preserver?

 

[ntb]

Yes but give the preservative a few days to dry.

 

[big-all]

looks about 6 or 7 planks shot from that picture
you can take wood thats fully exposed without treatment off any sort will last for years regardless off quality
wood can get wet very wet soaked over several months as long as the moisture content is constantly changing over quite a range it will not be effected
its around a constant19% the damage happens this can be debris at ground level 'a contact point with another component that will trap moisture or indeed a plant i suspect in the shade holding moisture
this is why you seldom get rot on the side the sun gets to as the moisture level varies far greater than in the shade

 

[LeadFarmer]

I removed the lower panel from my summer house today and cut a section from it to take as a sample to a local local fencing company. The panel came away easily when prised off with a wide bladed tool. They sell an almost identical board and gave me a sample to bring home to compare with my summerhouse. Thankfully it fitted just one so I'll be going back to buy a few from them..