Interlocking log cabin gaps & twisting causing water ingress - flexible sealant or structural fix?

[TimberDaze]

We have a Tuin interlocking log cabin built in Summer 2023. About three months in, horizontal gaps started appearing between log courses, and many logs have since twisted/distorted.

During heavy rain, water enters these open joints and sits, which has lead to early rot despite annual coats of a high-grade wood preserver.

To stop the ingress before winter, would a flexible sealant route work, or will it simply trap moisture and restrict seasonal expansion/contraction?

Photos attached show the wall profile and joint close-ups. Any advice on the best remedial approach would be appreciated. (I've reached out to Tuin customer care, but haven't been able to resolve it with them directly).

 

[Wayners]

Use a polymer like CT1 or Stixall.
Fill
Use waterbased paint over as a primer or topcoat. You have to use waterbased over first!
Use multi solve to clean up if you make mistakes

 

[TimberDaze]

Use a polymer like CT1 or Stixall.
Fill
Use waterbased paint over as a primer or topcoat. You have to use waterbased over first!
Use multi solve to clean up if you make mistakes

Many thanks for the CT1 suggestion, and the tip about using a water-based paint as a primer.

Before I seal, I'm also considering whether I should first try to mechanically pull the twisted logs back flat from the inside using a vertical timber batten with slotted expansion holes (to allow ongoing seasonal movement).

In your experience, is it worth trying to pull the bowed logs flush first, or is it better to leave them in their settled shape and rely entirely on the CT1 to bridge and seal the gap?

 

[Wayners]

I don't think you will move that.

I've got several patio slabs on a plank ATM so they don't scratch the new slabs under.
The plank is a bit twisted and the slabs have made no difference even with the weight

 

[opps]

I have assembled a couple of Tuin log cabins.

Do you have their toy guttering or no guttering?

I would be inclined to contact them.

@Wayners ' advice about CT1 is sound. It is slightly thinner than stixall.