Hot tubs and garden saunas can be impregnated from the outside with a good wood impregnation. You can also paint the outer surface with varnish-stain. From the inside, the sauna should be filled with paraffin oil, while the tubs are not maintained at all. For bathing in the tub, you can use salt, e.g. sea, medicinal or flavored, or all preparations for maintaining pool hygiene in accordance with their instructions for use. Remember to keep the sauna and hot tubs hygienically clean at all times.
Hygienic compliance with standards is confirmed by the Hygienic Certificate issued by the National Institute of Hygiene. Indispensable for public facilities and in the case of the need to maintain hygiene in direct contacts.