Hi don't know if anyone can help. I really don't know what to do about this..! I recently bought a corner summer house. My dad and his friend grafted so hard last Friday and Saturday building it. We put sealant around all the inside joins but couldn't paint it outside, as it then started pouring. Sunday afternoon I went in and it was drenched. Water leaking through the grooves of the shiplap tongue and groove and the walls and floor were wet. I spoke to the company I bought it off and they said it only had 1 coat treatment applied by the manufacturers and wouldn't be water proof until I applied a top coat. Now, I have no clue what this is, so asked, will the waterproof paint (wilkinsons garden paint) I've got be suitable . He said it would be fine but they only recommended their own brand paint. Also said I had to treat it asap. So I took a half day from work as it was forecast dry, so I could go home and paint. I called in to Homebase, just to get advice again, and they said the same, the paint should do the trick. So applied a second coat Tuesday, still wet the next day after rain. Should I try applying a third coat?! I'm now thinking maybe I shouldn't of applied the paint straight away and maybe should of got an actual clear wood preservative first, to go underneath. So my next quandary is, do I need to get all this fresh paint off?! And start from scratch again. Which I've read is a nightmare, messy and very time consuming, but if it has to be done, so be it. And if I have to strip it, don't know what to use for quickness or what wood preserve to then apply. Bearing in mind I am applying a water based coloured paint over the top. I've spoken to a few people who work with wood outdoors and they've said one coat of wood preservative, plus two coats of waterproof paints should be enough to stop water coming in, but the whole panels that face the direction of the wind/rain are wet to touch, as well as the rain streaks from it running inside. I've spoken to the company I bought it off again and theyve said it might have been put together wrong. But there was no other way the panels could face, as the lip on the bottom overhung the floor, and there was no lip needed at the top. Any advice at all would be much appreciated. I'm at a stand still here and getting really stressed! Thank you.