How much is the Deposit for a second hand house and can the Sellers avail of it after fees?

If you are the seller, you won't get any proceeds until any the sale has closed.

The 10% deposit is paid by the buyer, via their sol, to the vendor's sol.

At the signing of the contract, the buyer pays 10% deposit, to the vendor's sol.

The closing date is later.

My sol told me that if everybody works together, the closing date could be very soon after signing of contracts.

In my case, I think it was a week later.

At the closing date, the buyers sol transfers the large amount to the vendors sol.

Soon after that, my sol sent me the final settlement.

It was a document listing the sales receipts, less fees like estate agent and sol, etc.

The balance was paid to me, the vendor.

There are two stages in the sale or purchase of a house. Sale agreed and completion. You pay the deposit at sale agreed stage when you agree to buy/sell the house. The seller does not get the deposit money. It's held by the agent. If you're buying from a private seller without an agent, a solicitor should hold the money while contracts are being drawn up for completion of the sale. You should each have your own solicitor and they act in your interests to protect you.

The deposit doesn't have to be a specific amount. You can agree just a few thousand euros if it's going to the agent. It's usually more if it's going to a solicitor.

Drawing up contracts for completion can take a while because a 'search' has to be done by the purchaser's solicitor to make sure that everything is in order with the property. Also it allows time to have a survey done, finalize any mortgage etc.

On the day of completion, the purchaser pays the balance of the price of the house and it goes to the solicitor who transfers it to the seller after deducting his/her fees.

If you're from mainland Europe you may be accustomed to the system where the seller gets the deposit and can spend it :) and there is no need for a solicitor, just a notary.

Its not weird that you can't spend money that isn't actually yours yet.

That really does not mean the sale is going to go through, in Ireland.

Its not your money til closing.

"Weird that if the money is just sitting there the sellers can't avail of it even if every other party has taken their fees."

I think you're a bit confused about how the process works. Nobody has taken any fees. Nobody gets any money until the day the keys are handed over. This might help you to understand:

https://www.citizensinformation.ie/en/housing/owning-a-home/buying-a-home/steps-involved-buying-a-home/#:~:text=The%20legal%20process%20to%20buy,you%20with%20a%20loan%20pack.