How do I deal with my 7 yr old ds's "compulsion" to graffiti surfaces.

[TapselteerieO]

He has mild ASD, this is a huge problem because we live in a rented house and he tends to press hard leaving scores in the surface. I got really angry with him tonight and shouted at him - which I know isn't constructive on any level, but this has happened regularly and I just want him to stop. He told me today he wanted to write stuff all over the house, I told him that he was not to write on any surfaces in the house - then a few hours later my dd discovered it.

Today, it was a varnished wooden windowsill, deep scrapes and grooves, some writing.

He has free access to paper/pens - they are always available.

I have to be honest, the only way I stopped DS2 doing the same (ASD) was to remove the pens from his reach :(. I then tried giving them back to free access every couple of months or so and if graffitti happened they were removed straight away. He now doesn't do it anymore.

Could you maybe paint a large piece of wood with chalkboard paint & hang it in his room? If he draws/writes anywhere else bit on there he loses a privilege?

He has lost the use of the computer - quite a severe punishment, for the week.

I don't think he even used a pen/pencil to do the damage, there is no colour, just scraped varnish and grooves - it isn't a regular occurrence, that makes it more difficult to anticipate, we can go months and then he does it over several days. I will ask him tomorrow what he used, so fed up about it.

He doesn't seem to be interested in chalk, too messy, he seems to like the permanence of scraping into wood/walls.

Thanks for the replies.