Passive fire protection is an essential aspect of gypsum construction. Gypsum firewalls of various types (shaft walls, simple partitions, etc.) prevent fire from spreading without relying on mechanical means of control, such as sprinkling.

There is a lot of confusion in the field over area-separation firewalls and utility placement. I know that the GA has a position statement that clarifies criteria for the placement of utilities in the flanking walls on either side of a two-hour, steel H-stud, gypsum shaftliner panel area-separation wall.

Although Royal Bank of Scotland is back in loss on a so-called statutory basis, having made the tiniest of profits in the final three months of last year, that doesn't really tell the story of what has been going on at this semi-nationalised bank.

For the record, the statutory attributable loss was £528m in the three months to March 31, compared with a profit of £12m in the last quarter of 2010 and a £248m loss in the first quarter of 2010.

But, as is par for the course with big, complex universal banks, these numbers do almost as much to obscure as to enlighten.

They are, for example, heavily influenced by changes in the valuation of debt sold by Royal Bank of Scotland to investors and of credit insurance bought from taxpayers in the form of the Asset Protection Scheme.

There was a loss of not far off £1bn on these items. Now it's moot whether it really enhances our understanding of Royal Bank of Scotland's performance that the value of these contracts - which can't be broken at a moment's notice - have moved against RBS.

More important, I think, is that operating profits of RBS's retail and commercial operations are almost a fifth better than a year ago at £1.9bn, though a little bit lower than in the fourth quarter of 2010.

The trend at RBS's global banking and markets business - what most would call its investment banking arm - was more volatile. Operating profits were £1.1bn in the latest period, double what was generated in the final quarter of 2010, but a third less than the bumper first three months of last year.

For the bank as a whole, the charge for debts going bad seems to be on an unambiguously declining trend, from £2.7bn in the first quarter of 2010, to £2.1bn in the final quarter of last year, and just under £2bn in the latest quarterly figures.

As for other important measures, RBS is succeeding in widening the gap between what it charges for credit and what it has to pay to borrow (good for shareholders, not always welcomed by customers) - and overheads appear to be under control.

So there is progress towards re-establishing RBS as thriving, growing business, which could prosper without the benefit of exceptional support from taxpayers - although that progress goes by fits and starts rather than in one giant leap (witness, as with Lloyds, a big increase in losses on lending to the troubled Irish economy).

What will perhaps spark some controversy is that the provision of credit to small businesses fell 7%. And, once again, RBS puts this down to a weakness of demand rather than a lack of any determination on its part to supply - but that doesn't enlighten on whether it's the unattractive borrowing terms on offer that puts off some potential business borrowers.

Also RBS has gone on the record for the first time with its opposition to the proposal from the Independent Banking Commission that internal firewalls should be erected inside giant banks such as RBS.

RBS says that the Independent Banking Commission's recommendation that universal banks like it should erect internal firewalls, or should put their retail and investment banking operations into separate insulated subsidiaries, are "likely to add to bank costs - impacting both customers and shareholders -without the safety gains that the broader Basel process is delivering" (the Basel process is the global negotiations on strengthening banks).

It is also striking that RBS signals that it isn't overjoyed at the unilateral decision made yesterday by Lloyds to chuck in the towel in the banks' legal battle against the regulators' judgement that they should make comprehensive restitution to those mis-sold PPI loan insurance. The banks says: "a decision on appeal of the court case...has not yet been made as it relates to important other issues of retrospective regulation".

As I've mentioned before, if RBS follows Lloyds's lead and offers a comprehensive PPI settlement, that would probably cost the bank a bit more than £1bn, about a third of the cost to Lloyds.

And if we're in the business of comparing the two partly nationalised mega banks, Lloyds and RBS, both still look some way from being in a fit state to see taxpayers' huge stakes privatised at a profit to all of us.

However if Lloyds entered the reporting season looking as though it was nearer to privatisation than RBS, their respective latest results probably show RBS inching forward a bit in that journey and Lloyds perhaps retreating slightly.

Customized malware used to compromise physical and virtual firewalls