Flaking paint on the porch

[gregmcateer]

Not sure where I should post this, so Mods, please move if feel nececessary.

New porch sides made of a light coloured hardwood have been built around existing main post, the latter of which also had a new Oak block inserted below as the orginal, (100 years+) was rotting.

The joiner said to prime with Aluminium primer, then Dulux UC and Gloss - all of which I have done.

All except one area fine - but paint has bubbled up and when I pressed the bubble it released trapped water that ran for a few minutes! I scraped back further to let it dry out completely, then feathered in and repainted last year. Now same thing again!!

Hopefully the pictures will show. My finger is pointing to the join between new and old, which seems to be source of the problem.

I have seen chat of Holkham linseed oil paint - is this the answer once re-dried, or is there e.g. a fundamental design/construction flaw that I have to address first?

Hope someone can help #-o

 

[deserter]

Looks to me like you have a step between parts there, rain water will sit on that step and work its way behind the paint and into the timber. To the left of the area in your photo it appears you have a needing which will allow the water to run off and not to stand, is there anyway you could incorporate something similar into that step, or even plane the step out, making it a gradient instead.

Just my ideas lets see what others have to say.

 

[hanser]

A couple of things:

You need to ascertain where the rain is getting in. The 'step' may be the problem area or rain be be blowing in higher up and then running down to the area where the paint is blowing off. The water staining on the LHS indicates weeping from behind the joint where the planted piece meets the wall/panel. I'd be tempted to whip it off and see what's happening. Does the porch face SW and gets the prevailing wind/rain? Rain under pressure from the wind will push into the minutest of cracks. Also is there any faulty guttering above the area?

The two pieces of wood look very wet and need to be dry before you repaint. If you seal the wood wet, the paint will fail again whilst the wood will continue to rot.

Let's hope for a great summer :roll:

 

[gregmcateer]

Deserter and Hanser,

Many thanks for your replies. I was a little concerned about the join between the new vertical strip that runs down the length of the porch and the new oak post base, but the joiner was unconcerned - should have listened to my instinct!

It does face south, yes. I think I'd better do as you say and whip off the strip, (I think you called it 'planted piece') and have a look higher up.

Thanks again,

Greg