The oak frame may get a little dirty during and after the erecting process. Also, due to the moisture content of green oak, you may also notice natural tannins which cause black marks to appear on the oak.
The longer the frame is left to the elements the more staining will occur. We recommend that these marks are cleaned with an oxalic acid solution. The timing of the cleaning process is crucial; the frame needs to be enclosed to prevent re-staining from the weather, but it needs to be carried out early in the building process so other surface finishes are not affected.

Essentially there are no specific requirements for any maintenance of the oak frame itself other than what you may want to do for aesthetic purposes.
Oak frames do not require a surface finish. Natural sunlight will change the untreated exterior of the frame to a silvery grey. Depending on your preference, the original, lighter colour can be retained if the wood is treated or sealed before it is exposed to the elements. Remember though, this will require ongoing maintenance as the weather erodes the treatment off.
Indoors the oak will soften and pale, oxidising to a beautiful honey colour. Some people oil or wax the frame to their own colour and finish preference. Adding a treatment in kitchens where it helps to prevent stains from cooking or in bathrooms to protect against moisture is often preferred.
With any finish, we would recommend that you test a small area first to make sure you are happy with the end result.

As oak dries it changes it’s looks and characteristics. The more it dries the lighter and stronger it gets. Using an experienced oak framing company ensures that joints are designed so that as the timber dries the joints lock together to increase that strength. As this happens you should expect to see some changes to the characteristics of the oak members. As the frame settles it will create its own unique splits which are entirely normal and part of the settling process and part of the charm of an organic structure.
You can, however, help the frame to settle in by being gentle with it when completing the build. The frame, being built in green timber, will shrink over time but the length of the shrinking process will be affected by the temperatures it is exposed to. If large heaters are used to dry out the building, this harsh and sudden heat is likely to increase shrinkage splits. Similarly, sudden high levels of heating will increase the chance of the splits being more pronounced. While this will not damage the structural strength of the frame it will make the frame look more rustic.

No. Oak is extremely resistant to insect infestation and in the UK it can be exposed externally without any need for treatment.