Building Contractors and Professional Site Inspections
- Building Design Expert
- 8 years ago
Walking onto a building site under a new contractor can sometimes be a testing experience. He has won the contract fair and square under your strict tender requirements, and therefore jumped through all the required hoops that allows him to have created the environment that you have just walked into. Now it’s his turn; to an extent anyway. It’s his site and his rules, notwithstanding that he must accommodate you as the architect, or contract administrator.
This may be the first time you have met the site manager, and of course, he, you. So neither wants to get off on the wrong foot. You need to exude confidence in your expectations of the project, its design and the reasons it has been constructed in the way shown on the drawings. You want to remain affable, reasonable and approachable; adopting that middle ground between ‘anal’ site inspector (don’t take that too literally, please) who must have everything your way, and the building designer who doesn’t know when to compromise, so just does.
At the pre-start meeting you made quite clear the elements of the build you had earmarked in your own mind that may either require a considered level of attention on the contractors part, or those notorious items that so often can be the cause of mid-contract angst, like mortar droppings in cavities, or non protection of brick and block both pre and post laying. So anything less than surgical efficiency would not do. But whether of course the contractor has picked up your emphasis as you think you have communicated it remains to be seen.
By your second visit it’s clear the contractor would like to impress. He’s got the over-site laid and he has left sufficient DPM flapping in the breeze so that it can be laid fully into the next inner leaf bed course. In his view he has gone one better than you could ever have dreamed in keeping damp at bay.
To be fair, this guy, like the majority of site managers, has come through his early industry career as a joiner. The conclusion is that joiners are the one trade that conceivably have an input into every, or at least most stages of a building project, and therefore a comprehension of what is required. Importantly they have the experience of physically carrying it out, or at least witnessing it. Therefore a majority of site managers would seem to have a joinery background, and may have little formal training or qualifications in every aspect of building design. If they did they would be contract administrators would they not? Some technical design issues will remain the architect, or CA’s domain alone. The contractor is there to show how best to achieve them.
So you get ready for the masked surprise when you look him squarely in the face and ask him to ensure the DPM is cut back to slab level, and under no circumstances is it to be dressed into a bed joint, as the mortar and DPM cannot bond and will form a lateral slip plane along that bed joint if he does.
Good, so you have established a level in your working relationship; hopefully in a way that causes no loss of face or embarassment. After all we are only at DPC with a long way to go. With any luck that little nugget you have just tossed across will have been well received and stored away for future admonishment to a fellow site worker who tries to perform alchemy using polythene and mortar.
The site manager calls you: There are a couple of options available to resolve the drainage diversion and he wants to know which one you would prefer? You respond by asking which is the best solution as far as he is concerned? There was probably a fag paper between the options, so if it’s easier for the contractor to do it one way rather than the other, then that’s the choice.
Even the contractor who wants to tuck the polythene DPM into the DPC bed joint, will carry a wealth of salient knowledge that will often exceed yours. So it’s worth tapping into that at every opportunity to get the best of both worlds – Using good on-site experience, and letting the contractor do things the most familiar way possible; as long as his way is agreeable of course.
One of the most common misdemeanours, in fact I cannot remember a project when this hasn’t cropped up, is allowing walled masonry to get rained on. Even if the contractor has the presence of mind to protect the top and exposed recently walled faces, he seems more than willing to accept soaking wet blocks from his supplier and let his brick layer wall them. It seems one or the other will usually apply. This is different to an experienced brickie brushing some water onto a particularly porous brick or block on a very hot day to stop it sucking the life out of the mortar on contact. Site skills and knowledge; you cannot buy, or rent it. Either it’s there or it isn’t. But we draw the line at what boils down to the lazy options: The blocks are wet. We should get some dry ones, but that would take too long and we’re already a day behind, so the contractor walls them anyway.
Like so many instances in building construction, the contractor carrying out work other than to the letter of the paragraph, on the page, in the book, is not necessarily the end of the world. Walling wet blocks may lead to some joints cracking, maybe air tightness issues and certainly a loss of bond, but the building is unlikely to fail as a consequence. The view taken by the site inspector, and or contract administrator needs to often be delivered with an holistic wrapper.
There are often a number of ways to skin any given cat. Having said that it can often be the case that we have to use a certain size knife to get the best results. Just remembering to keep it sharp and not to cut too deep can be a challenge.