Trying to cope with massive damage to the home and possessions

Our high functioning 14 year old grandson to whom we are legal guardians is pulling our house down around our ears! We get damage when he is in meltdown and we get damage when he is happy or bored (usually sensory issues) and its becoming harder and harder to keep a decent home around us.

Goodness knows I'm no longer houseproud...that was beaten out of me years ago but we are finding it hard to keep just the neccessities that you would keep around any home. Anything that isn't huge gets hurled at walls and down the stairs, anything huge will often get tipped over (wardrobes etc). Glasses, cups, saucers, plates, doors get kicked and split, lining paper (we don't wallpaper anymore just paint over the lining paper) gets stripped off, the stair carpet got ruined when he threw a pot of paint down the stairs that hit the stairwell and exploded everywhere. We eventually got the insurance to pay out for about half of what we needed to get redecorated and a new stair and landing carpet but within a week of the new one being down our grandson had started to pull tufts out with his teeth (never done that before). Now the stair carpet is balding badly all the way down on the edge of the steps. Yesterday morning he wanted something that was being washed in the washing machine and wouldn't wait....he broke the washing machine trying to get it out...new washing machine bought same day. If another person tells me that they can't see how an autistic child is more expensive to raise than a NT child I will spit in their eye!!! We pile our possessions into rooms that we keep locked to protect them or they wont last five minutes. Its hard to remember to lock the doors behind you in your own home. This week's tally of damages are: one washing machine, a broken printer, numerous paving slabs in the garden (broke into the shed and got a hammer out) items of his own clothing (thread pulling until the item falls apart, and the top to a George Forman grill. Last week there was stuff broken and next week will be no different I shoudn't think. This year so far we have had salt poured into my steam iron, a hose pipe turned on a poked through the boiler vent outside flooding the boiler and kitchen, a hole burned in his roller blind ( he found the one fire lighter we have hidden in a top locker in the kitchen) and a patch of his carpet melted, the plastic coating on my airer melted, the arial on my digital radio snapped off and chewed (would you believe), various things drawn on or snipped when he found some scissors, my lovely polished floorboards in the bathroom pulled to pieces (he found a crack and started work on it), a broken shower, and various broken locks where he has kicked doors in to find things he wants. And.....amazingly we are still sane...well sort of haaaaaa.