Thank you for your answer and I did think of cutting the rods at a 45 degree angle and joining them together but the thing is the rods have to be able ...

hello I need to know how to join two 9.5mm wooden rods on a 90 degree angle. I have no idea how to do it I don't have any special tools jigs or guides ...

Thanks the reason I asked about the spacers is cos @JoeAzza said to use 75-100mm spacers

What is the difference between foil board and polystyrene insulation. And does the spacers have to be 75 to 100mm thick or can they be like 10mm thick ...