common defects in building

7/24/2019 common defects in building

1/6

Related

Sections F. Common Defects in Buildings - Structural

32. Recently, some concrete chips have fallen fromthe ceiling in my kitchen.

Thereare rusty steel bars and the area in question measures about 300 x

400mm. There are also similar patches found in the toilet and staircase.

How canwerepair them?

3.2.1 (b)

4.1.1 (a)

4.3.4

A. A diagonalcrack across w alls or structuralelem ents usually has structural

im plications particularly w hen such phenom enon repeats in flats above and

below your unit. The crack is likely to be caused by som e form ofstructural

m ovem ents ofyourbuilding. You should notify the O w ners'C orporation and

the property m anagerofsuch cracks. The O w ners'C orporation orthe property

m anager should approach ow ners ofotherflats to identify the extentofthe

problem . A Registered StructuralEngineer(RSE)should be appointed to carry

outan investigation, forrevealing the cause ofsuch cracks and propose the

rem edialw orks.

33. Recently, some concrete chips have fallen fromthe ceiling in my kitchen.

Thereare rusty steel bars and the area in question measures about 300 x

400mm. There are also similar patches found in the toiletand staircase.

How canwerepair them?

3.2.1 (b)

3.2.1 (e)

4.1.1 (a)

4.3.4

A. Answ erchanged to be This defectis com m only know n as concrete spalling

and can be due to a variety ofcauses e.g.w aterleakage from the floorabove,

high hum idity conditions ofthe kitchen, bathroom s,etc.causing the steelbars

to rustand debond the concrete cover. You are advised to engage a building

professionalto investigate forthe cause(s)and suggestrepairm ethods to the

affected area.

Ifthe concrete spalling isdue to w aterleakage from the floorabove,the ow ner

ofthe said unitshould be inform ed ofsuch situation and asked to carry out

the necessary repairw orksto preventrecurrence ofthe sam e defectafteryour

repair.

G. Common Defects in Buildings - Leakage

34. My window sill often leaksattimesof heavy rainfall and typhoon. Wehave

repaired theplaster andpaintunder thewindowseveral times, buttheleakage

still persists. Whatshould I do?

3.2.1 (b)

3.2.1 (e)

3.2.1 (f)

A. M erely repairing the plasterand paintunderneath the w indow sillm ay not

be sufficientforthe purpose. There could be a num berofpossible causes

e.g.crackson externalw all,honeycom b concrete,defective sealantatw indow ,

etc. You should seek the advice from a building professionaloratleastan

experienced w indow contractorto identify the exactcause(s)ofthe leakage

and engage a com petentcontractor to carry outthe repair w orks. U poncom pletion ofthe repair, you should also ask the contractor to carry outa

w atertestto ensure thatno furtherleakage w illoccur.

FRE Q U EN TLY A S K ED Q U ES TIO N S 190


2/6

Related

Sections35. I liveonthetopfloor. Recently, thetelephonecompanyhasinstalleda machine

roomand some antennae on the roof. Then water starts seeping through

my ceiling. Whatcan I do?

3.2.1 (b)

3.2.1 (e)

4.1.3 (a)4.6.3

A. There m ightbe a possibility thatw hen the telephone com pany installed the

m achine room and antennae on the roof,they have dam aged the w aterproofing

layerresulting in w aterseepage to your flat. You should notify the propertym anager and the O C ofthis problem . They should requestthe telephone

com pany to carry outan investigation to ascertain w hetherthe seepage is

caused by theirw orks. Ifpositive,the telephone com pany w illhave to arrange

forthe necessary repairs.

H ow ever,ifthere is no directproofofsuch responsibility,the O C should take

up the responsibility to repairifthe roofis com m only ow ned by the co-ow ners

ofthe building.

36. I received a complaintfromthe tenantdownstairs that the floor of my toilet

is leaking. Whatcan I do? Whatis themosteffective repair method?

3.2.1 (b)

3.2.1 (e)

4.1.3 (b)

4.1.3 (e)

A. Identifying the source ofw aterleakage is notan easy task. You are therefore

advised to engage a building professionalto carry outa detailed investigation,

including the inspection ofthe flatbelow . The leakage could either com e

from the defective w ater supply or drainage pipes or due to defective

w aterproofing layer ofyour toilet. Itcould also com e from other external

sources and itis only because yourtoiletis directly above, you have naturally

becom e the prim e suspect. O nce the source(s)ofleakage is identified, the

appropriate repairm ethod can be w orked outaccordingly.

37. I know that the unit above has carried out some alterations to their kitchen

and toilet. Sincethenmyceilinghasbeen leakingand theplaster keptfalling

off. How canI ask the flatabove to stop the leakage?

3.2.1 (e)

3.3.2 (e)4.1.3 (b)

4.1.3 (e)

5.2.6

A. You should reportthe case to the Food and Environm entalH ygiene D epartm ent

(FEH D)fortheirofficers to carry outan inspection ofthe floorabove to verifythatthe leakage is,in fact, originated from the flatabove. Ifitis found that

the leakage com es from the drains in the flatabove, the FEH D w illissue a

nuisance notice to the ow ner ofthe flatabove to requestfor the necessary

repairw orks in order to stop the leakage and abate nuisance.The problem

w illbe referred to the W aterSupplies D epartm entifthe leakage is from w ater

supply pipes.You can also requestthe ow nerofthe floorabove to carry out

repairw orksto yourflatdue to dam age caused by the said leakage.

191 FRE Q U EN TLY A S K ED Q U ES TIO N S


3/6

Related

Sections H. Common Defects in Buildings - Finishes

38. I have noticed that there are many hair-line cracks on the bedroomwalls,

and some paint peeled off. The cracks do nothave a specific pattern and

spread over a largearea. Whatis thecause? Isthereany danger?

3.2.1 (b)A. These hair-line cracks are usually shrinkage cracks developed w ithin the plaster

layerofthe w alls. They w illaffectthe appearance ofthe w allfinish butdo

notnorm ally cause structuralhazards.

Anotherpossible reason forthis defectis thatthe plaster layerhas detached

from the brick orconcrete w all. U ndersuch circum stances,ifyou tap the w all

surfaces, you w illheara hollow sound. Any "hollow "areas ofplasterw ork

should be rem oved w ith the w allsurface re-plastered w ith suitable key and

re-painted to avoid collapse offinishes.

39. I found thedoor frameof thetoiletand theskirting board nextto itdarkened

and some fine dust of wood often fell on the floor. Tapping themgave a

hollowsound. Whatcould betheproblem? How to repair them?

3.2.1 (e) A. The sym ptom s look like thatthe darkened doorfram e and the skirting board

are suffering from term ite attacks. The term ites are attracted to softordam p

w ood. You should appointa pestcontrolcom pany (contactno. of these

com panies can be found in the Yellow Pages)to carry outan investigation

and subsequenttreatm entw orks. Allinfected tim bershould be rem oved.

Ifthe dam pness in the tim ber is due to w ater leakage, you m ightalso need

to engage a building professionalto locate the source ofleakage and to carry

outthe necessary repairw orks.

I. Common Defects in Buildings - Slopes and Retaining Walls

40. There has been lots of vegetation growing out fromthe small holes of theslope. Since then there hasalso been no morewater coming out fromthe

holes. Isthereany danger and do we need to do something?

3.2.1 (d)

4.1.4

A. Itis likely thatthe w eep holes ofthe slope are being blocked by the vegetation

grow th. This m ay cause a build up ofw aterpressure behind the slope, w hich

m ighteventually lead to its failure. Property m anagem entstafform aintenance

w orkers should clearaw ay allthe vegetation and blocking m aterials from the

w eep holes. H ow ever,ifthe clearing outw orks cam e to no effect,i.e.,the

w eep holes are stillnotdraining w ateroutfrom the slope, you should appoint

a geotechnicalengineer to carry outan investigation on the slope as soonas possible.



4/6

Related

Sections41. Repairworksarebeingcarried outontheslopeofour adjacentlot. Recently,

wehavereceived a Repair Order fromtheBuildingsDepartment(BD)saying

that our slope at the back requires investigation and repair. Would it be

possible that theslope works at the adjacent lothave caused the trouble?

How should wepursuethematter to identify theresponsible culprit?

4.1.4

4.2.2 (d)

A . You should appoint an Authorized Person (A P) to coordinate the repairw orks as requested by the BD . The A P w illalso need the assistance of

a Registered Structural Engineer (RSE) or a Registered G eotechnical Engineer (RG E).

The AP/ RSE/RG E w ill jointly carry out an investigation of the slope and

recom m end repair m ethods. Their findings should be able to clarify w hether

the repair w orksat the adjacent slope has affected yours.

Ifpositive, you should contactthe ow ner ofthe adjacent slope requesting

them to cause the carrying out the necessary rectification w orks under

the supervision of preferably your A P/ RSE/ RG E.If the ow ner of the

adjacent slope does not respond to your request, you should carry outthe w orks and recoveryourlosses via legalaction.

O therw ise, you should carry out the necessary repair w orks under the

supervision of your AP/ RSE/ RG E at your ow n expenses.

42 There are cracks on the surface of the slope at the back of my building. How

can I know whether it is safe? Who is responsible for the repair of such

slope?

3.2.1 (d)

5.2.2

A . Public can check the m aintenance responsibility (M R)ofa slope by m aking

enquiries to the G eotechnical Engineering O ffice of C ivil Engineering and

D evelopm ent D epartm ent and the Lands D epartm ent. Such inform ation is also

available in their w ebsites being http:/ / hkss.cedd.gov.hk/ hkss/ eng/ slopeinfo/

siswelcome.asp andwww.slope.landsd.gov.hk/ smris respectively.

If cracks occur on the slope surfaces, you should notify the O C and

property m anager im m ediately and check the M R ofthe slope to confirm

the party responsible forthe slope repairw orks.

If the M R falls on the ow ners of your building, then the O C or property

m anager should arrange to appointa geotechnicalengineer to investigate

the cause and propose the corresponding rem edialw orks.

If the M R falls on others e.g. the ow ners of the adjoining lot, the O C or

property m anager should try to requestthe ow ners of the adjoining lotto

carry out the necessary investigation and repair w orks. If itcom es to no

avail,you should reportto the G EO orBD fortheirfollow up action. Should

circum stance w arrant, an investigation and repairorder under Section 2 7A

ofthe Buildings O rdinance m ay be issued by the BD requiring the responsibleow ners to carry outthe necessary w orks.



5/6

Related

SectionsQ uestion 4 2 (co ntinues)

A s a tem porary m easure, your O C or property m anager should prom ptly

appointa registered specialistcontractorin the site form ation w orks category

to sealup the cracks w ith cem entm ortarto preventthe ingressofsurface w ater

into the slope.

Appendix 7 43 Water is draining out fromthe weep holes of the retaining wall adjoining

tomybuilding.WhatshouldI do? Whatarethecausesandwhoisresponsible?

A. W aterdraining outfrom the w eepholes ofretaining w alls in rainy days are

indications thatsuch w eepholes are functioning properly to discharge the

rainw atercollected from the slope. In such cases,no follow -up is required.

O therreasons are bursting ofw atersupply pipes (ifthe discharge is continuous,

clearand w ithoutsm ell),drainage pipes (ifthe discharge is m uddy and sm elly)or storm w ater drains (ifthe discharge occurs m ainly on rainy days and is

usually very clearbutfound unusually excessive and gushing out)etc behind

the retaining w all.

N aturally,the ow ners ofthe defective drains and pipes should be responsible

forstopping the abnorm aldischarge. You should notify the property m anager

orthe O C im m ediately ofsuch w ho w illin turn notify the ow ners concerned.

From a safety pointofview , any buried w ater-carrying services w hich are

found to be dam aged orleaking should be repaired w ithoutdelay. Ifthe

concerned ow nersfailto co-operate,you should notify the BuildingsDepartm entfortheirfollow up action. Should circum stance w arrant,an investigation and

repairorder under Section 27C ofthe Buildings O rdinance m ay be issued

by the BD requiring the responsible ow ners to carry outthe necessary w orks.

J . Common Defects in Buildings - Building Services

44. Recently, the flushing water supply frequently stops. What could be the

possible causes? How should wedeal with thedefects?

3.2.1 (c)

4.1.2 (d)

A. The stoppage ofthe flushing w ater supply w as likely to be caused by the

failure ofthe w ater pum p w hich pum ps the w ater up to the storage tank at

roof level. This m ight be due to im proper m aintenance or thatthe pum p

sethas com e to the end ofits service life. The pum p setshould either be

com pletely overhauled orreplaced.

Breakage ofthe supply pipes could be an easily detectable cause as large

quantity ofw aterw illflow outfrom the defective point. Blockage ofpipes

could be anotherpossible reason especially in cases w here sea-w aterhasbeen used forflushing.



6/6

Related

Sections45. Our fresh water supply isoften rusty and dirty. Theupper floorsdonothave

sufficientpressure to operate thegas water heaters. What is theproblem

and whatcanwedo to rectify?

3.2.1 (c)

4.1.2 (d)

5.2.9

A. Rustand dirtin the fresh w ater supply m ightbe due to rusty pipes or dirty

supply tank. The rusty pipes should be replaced and the supply tank properly

cleaned.

Ifthere is insufficientpressure to operate the gas w aterheaters in the upper

floors,eitherblockage ofthe supply pipes orvalves orinsufficienthead pressure

from the rooftank could be the causes. The w hole system should be checked

and, blocked pipes should be cleared or replaced. Should there stillbe

insufficientpressure,you w illhave to seek advice from a building professional

on how to increase the w ater pressure, possibly by m eans ofinstalling a

pressurizing pum p to the supply system serving the upperfloors. Please note

thatany alteration to the w atersupply system w ould require endorsem entfrom

the W aterSupplies D epartm ent.

46. How do we know that the fire service installations (FSI) in our building are

effectiveand meetcurrentstandards?

3.2.1 (c)

4.1.2 (b)

A. Basic fire service installations in a building generally include hose reels,fire

extinguishers,fire alarm system s orautom atic sprinklersystem s (notfordom estic

portion). To ensure thatthese installations w ork efficiently atalltim es, a

Registered Fire Service Installation C ontractor (RFSIC )should be em ployed

by the O C to m aintain,inspectand certify the installation atleastonce every

year. W hen the FSIis found notw orking properly ordam aged, im m ediate

repairshould be carried out.

In the case ofold buildings,itis likely thatthe installation are notup to current

standards. There are new legislations requiring old buildings to com ply w ith

currentfire safety standards. The O C ofyourbuilding should consulta building

professionalorRFSIC to see ifim provem entw orksto yourbuilding are required.

Ifproperly m aintained,FSIshould be able to provide the necessary protectionto the occupiers. Should better standards be targeted, you can requestthe

M anagem entC om m ittee ofyourO C to review the situation w ith the appointed

RFSIC to discuss possible im provem entw orks. Itw ould also be advisable to

consulta building professionalifm ajorim provem entw orks are anticipated.


Documents

common defects in building